YOUR GUIDE TO

Healthy Sleep

Your Guide to 

Healthy Sleep 

NIH Publication No. 11-5271 

Originally printed November 2005 

Revised August 2011 

Contents
 

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
 

What Is Sleep? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
 

What Makes You Sleep? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
 

What Does Sleep Do for You? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
 

Your Learning, Memory, and Mood . . . . . . . . . . . . . . . . . . . . . . . . 12
 

Your Heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
 

Your Hormones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
 

How Much Sleep Is Enough? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
 

What Disrupts Sleep? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
 

Is Snoring a Problem? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
 

Common Sleep Disorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
 

Insomnia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
 

Sleep Apnea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
 

Restless Legs Syndrome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
 

Narcolepsy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
 

Parasomnias (Abnormal Arousals) . . . . . . . . . . . . . . . . . . . . . . . 51
 

Do You Think You Have a Sleep Disorder? . . . . . . . . . . . . . . . . . . . . . . . . . 53
 

How To Find a Sleep Center and Sleep Specialist . . . . . . . . . . . . . . . . . . 56
 

Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
 

For More Sleep Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
 

Contents 

1 

 

 

Introduction
 

Think of your daily activities. Which activity is so important you 

should devote one-third of your time to doing it? Probably the first 

things that come to mind are working, spending time with your 

family, or doing leisure activities. But there’s something else you 

should be doing about one-third of your time—sleeping. 

Many people view sleep as merely a “down time” when their brains 

shut off and their bodies rest. People may cut back on sleep, thinking it won’t be a problem, because other responsibilities seem much 

more important. But research shows that a number of vital tasks 

carried out during sleep help people stay healthy and function at 

their best. 

While you sleep, your brain is hard at work forming the pathways 

necessary for learning and creating memories and new insights. 

Without enough sleep, you can’t focus and pay attention or respond 

quickly. A lack of sleep may even cause 

mood problems. Also, growing 

evidence shows that a chronic 

lack of sleep increases your risk 

of obesity, diabetes, cardiovascular disease, and infections. 

Introduction 
2 

 

 

 

 

 

Your Guide to Healthy Sleep 

Despite growing support for the idea that adequate sleep, like 

adequate nutrition and physical activity, is vital to our well-being, 

people are sleeping less. The nonstop “24/7” nature of the world 

today encourages longer or nighttime work hours and offers 

continual access to entertainment and other activities. To keep up, 

people cut back on sleep. 

A common myth is that people can learn to get by on little sleep 

(such as less than 6 hours a night) with no adverse effects. Research 

suggests, however, that adults need at least 7–8 hours of sleep each 

night to be well rested. Indeed, in 1910, most people slept 9 hours a 

night. But recent surveys show the average adult now sleeps fewer 

than 7 hours a night. More than one-third of adults report daytime 

sleepiness so severe that it interferes with work, driving, and social 

functioning at least a few days each month. 

Evidence also shows that children’s and adolescents’ sleep is shorter 

than recommended. These trends have been linked to increased 

exposure to electronic media. Lack of sleep may have a direct effect 

on children’s health, behavior, and development. 

Chronic sleep loss or sleep disorders may 

affect as many as 70 million Americans. 

This may result in an annual cost of 

$16 billion in health care 

expenses and $50 billion in 

lost productivity. 
3 

What happens when you don’t get enough sleep? Can you make up 

for lost sleep during the week by sleeping more on the weekends? 

How does sleep change as you become older? Is snoring a problem? 

How can you tell if you have a sleep disorder? Read on to find the 

answers to these questions and to better understand what sleep is 

and why it is so necessary. Learn about common sleep myths and 

practical tips for getting enough sleep, coping with jet lag and 

nighttime shift work, and avoiding dangerous drowsy driving. 

Many common sleep disorders go unrecognized and thus are not 

Introduction 

treated. This booklet also gives the latest information on sleep 

disorders such as insomnia (trouble falling or 

staying asleep), sleep apnea (pauses in 

breathing during sleep), restless legs 

syndrome, narcolepsy (extreme daytime 

sleepiness), and parasomnias (abnormal 

sleep behaviors). 

It’s important to tell your 

doctor what you are 

experiencing, so you can 

help your doctor diagnose 

your condition.

SZE-PING 

“ 

” 
4 Your Guide to Healthy Sleep 

What Is Sleep?
 

Sleep was long considered just a block of time when your brain and 

body shut down. Thanks to sleep research studies done over the 

past several decades, it is now known that sleep has distinct stages 

that cycle throughout the night in predictable patterns. How well 

rested you are and how well you function depend 

not just on your total sleep time but on how much 

sleep you get each night and the timing of your 

sleep stages. 

Your brain and body functions stay active throughout sleep, and each stage of sleep is linked to a 

specific type of brain waves (distinctive 

patterns of electrical activity in the brain). 

Sleep is divided into two basic types: 

rapid eye movement (REM) sleep and 

non-REM sleep (with three different 

stages). (For more information, see 

“Types of Sleep” on page 5.) Typically, 

sleep begins with non-REM sleep. In 

stage 1 non-REM sleep, you sleep lightly 

and can be awakened easily by noises or 

other disturbances. During this first stage 

of sleep, your eyes move slowly, your 

muscles relax, and your heart and breathing rates begin to slow. You then enter 

stage 2 non-REM sleep, which is defined 

by slower brain waves with occasional 

bursts of rapid waves. You spend about 

half the night in this stage. 

When you progress into stage 3 nonREM sleep, your brain waves become 

even slower, and the brain produces 

extremely slow waves almost exclusively 

(called Delta waves). 
5 

 

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Stage 3 is a very deep stage of sleep, during which it is very difficult 

to be awakened. Children who wet the bed or sleep walk tend to do 

so during stage 3 of non-REM sleep. Deep sleep is considered the 

“restorative” stage of sleep that is necessary for feeling well rested 

and energetic during the day. 

Types of

 Sleep

Non-REM Sleep REM Sleep 

Stage 1: Light sleep; easily 

awakened; muscles 

relax with occasional 

twitches; eye 

movements are slow. 

Stage 2: Eye movements stop; 

slower brain waves, 

with occasional bursts 

of rapid brain waves. 

Stage 3: Occurs soon after you 

fall asleep and mostly 

in the first half of the 

night. Deep sleep; 

difficult to awaken; 

large slow brain 

waves, heart and 

respiratory rates are 

slow and muscles are 

relaxed. 

Usually first occurs 

about 90 minutes 

after you fall asleep, 

and longer, deeper 

periods occur during 

the second half of the 

night; cycles along with 

the non-REM stages 

throughout the night. 

Eyes move rapidly 

behind closed eyelids. 

Breathing, heart rate, 

and blood pressure are 

irregular. 

Dreaming occurs. 

Arm and leg muscles 

are temporarily 

paralyzed. 

Types of Sleep 

During REM sleep, your eyes move rapidly in different directions, even 

though your eyelids stay closed. Your breathing also becomes more 

rapid, irregular, and shallow, and your heart rate and blood pressure 

increase. Dreaming typically occurs during REM sleep. During this 

type of sleep, your arm and leg muscles are temporarily paralyzed so 

that you cannot “act out” any dreams that you may be having. 

What Is Sleep? 
6 Your Guide to Healthy Sleep 

 

 

 

 

 

You typically first enter REM sleep about an hour to an hour and a 

half after falling asleep. After that, the sleep stages repeat themselves continuously while you sleep. As you sleep, REM sleep time 

becomes longer, while time spent in stage 3 non-REM sleep becomes 

shorter. By the time you wake up, nearly all your sleep time has 

been spent in stages 1 and 2 of non-REM sleep and in REM sleep. 

If REM sleep is severely disrupted during one night, REM sleep time 

is typically longer than normal in subsequent nights until you catch 

up. Overall, almost one-half of your total sleep time is spent in 

stage 2 non-REM sleep and about one-fifth each in deep sleep (stage 3 

of non-REM sleep) and REM sleep. In contrast, infants spend half 

or more of their total sleep time in REM sleep. Gradually, as they 

grow, the percentage of total sleep time they spend in REM continues to decrease, until it reaches the one-fifth level typical of later 

childhood and adulthood. 

Why people dream and why REM sleep is so important are not well 

understood. It is known that REM sleep stimulates the brain 

regions you use to learn and make memories. Animal studies 

suggest that dreams may reflect the brain’s sorting and selectively 

storing new information acquired during wake time. While this 

information is processed, the brain might revisit scenes from the day 

and mix them randomly. Dreams are generally recalled when we 

wake briefly or are awakened by an alarm clock or some other noise 

in the environment. Studies show, however, that other stages of 

sleep besides REM also are needed to form the pathways in the 

brain that enable us to learn and remember. 
7 

 

 

 

 

 

 

 

 

 

What Makes You Sleep?


Although you may put off going to sleep in order to squeeze more 

activities into your day, eventually your need for sleep becomes 

overwhelming. This need appears to be due, in part, to two substances your body produces. One substance, called adenosine, 

builds up in your blood while you’re awake. Then, while you sleep, 

your body breaks down the adenosine. Levels of this substance in 

your body may help trigger sleep when needed. 

A buildup of adenosine and many other complex factors might 

explain why, after several nights of less than optimal amounts of 

sleep, you build up a sleep debt. This may cause you to sleep longer 

than normal or at unplanned times during the day. Because of your 

body’s internal processes, you can’t adapt to getting less sleep than 

your body needs. Eventually, a lack of sleep catches up with you. 

The other substance that helps make you sleep is a hormone called 

melatonin. This hormone makes you naturally feel sleepy at night. 

It is part of your internal “biological clock,” which controls when 

you feel sleepy and your sleep patterns. Your biological clock is a 

small bundle of cells in your brain that works throughout the day 

and night. Internal and external environmental cues, such as light 

signals received through your eyes, control these cells. Your biological clock triggers your body to produce melatonin, which helps 

prepare your brain and body for sleep. As melatonin is released, 

you’ll feel increasingly drowsy. Because of your biological clock, 

you naturally feel the most tired between midnight and 7 a.m. You 

also may feel mildly sleepy in the afternoon between 1 p.m. and 

4 p.m. when another increase in melatonin occurs in your body. 

Your biological clock makes you the most alert during daylight 

hours and the least alert during the early morning hours. Consequently, most people do their best work during the day. Our 24/7 

society, however, demands that some people work at night. Nearly 

one-quarter of all workers work shifts that are not during the 

daytime, and more than two-thirds of these workers have problem 

sleepiness and/or difficulty sleeping. Because their work schedules 

What Makes You Sleep? 
8 Your Guide to Healthy Sleep 

are at odds with powerful sleep-regulating cues like sunlight, night 

shift workers often find themselves drowsy at work, and they have 

difficulty falling or staying asleep during the daylight hours when 

their work schedules require them to sleep. 

The fatigue experienced by night shift workers can be dangerous. 

Major industrial accidents—such as the Three Mile Island and 

Chernobyl nuclear power plant accidents and the Exxon Valdez oil 

spill—have been caused, in part, by mistakes made by overly tired 

workers on the night shift or an extended shift. 

Night shift workers also are at greater risk of being in car crashes 

when they drive home from work during the early morning hours, 

because the biological clock is not sending out an alerting signal. 

One study found that one-fifth of night shift workers had a car crash 

or a near miss in the preceding year because of sleepiness on the 

drive home from work. Night shift workers are also more likely to 

have physical problems, such as heart disease, digestive troubles, and 

infertility, as well as emotional problems. All of these problems may 

be related, at least in part, to the workers’ chronic sleepiness, possibly because their biological clocks are not in tune with their work 

schedules. See “Working the Night Shift” on page 9 for some 

helpful tips if you work a night shift. 

Other factors also can influence your need for sleep, including your 

immune system’s production of hormones called cytokines. Cytokines are made to help the immune system fight certain infections or 

chronic inflammation and may prompt you to sleep more than 

usual. The extra sleep may help you conserve the resources needed 

to fight the infection. Recent 

studies confirm that being well 

rested improves the body’s 

responses to infection. 

People are creatures of 

habit, and one of the 

hardest habits to break is 

the natural wake and 

sleep cycle. Together, a 

number of physiological 

factors help you sleep 

and wake up at the 

same times each day. 
9 

 

 

Consequently, you may have a hard time adjusting when you travel 

across time zones. The light cues outside and the clocks in your new 

location may tell you it is 8 a.m. and you should be active, but your 

body is telling you it is more like 4 a.m. and you should sleep. The 

end result is jet lag—sleepiness during the day, difficulty falling or 

staying asleep at night, poor concentration, confusion, nausea, and 

generally feeling unwell and irritable. See “Dealing With Jet Lag” on 

page 10. 

Working the 
 

 Night Shift
 Try to limit night shift work, if that is possible. If you must work 

the night shift, the following tips may help you: 

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Increase your total amount of sleep by adding naps and 

lengthening the amount of time you allot for sleep. 

Use bright lights in your workplace. 

Minimize the number of shift changes so that your body’s 

biological clock has a longer time to adjust to a nighttime 

work schedule. 

Get rid of sound and light distractions in your bedroom 

during your daytime sleep. 

Use caffeine only during the first part of your shift to 

promote alertness at night. 

If you are unable to fall asleep during the day, and all else fails, 

talk with your doctor to see whether it would be wise for you 

to use prescribed, short-acting sleeping pills to help you sleep 

during the day. 

Night Shift
 

What Makes You Sleep? 
10 Your Guide to Healthy Sleep 

Dealing With 

 Jet Lag

Be aware that adjusting to a new time zone may take several 

days. If you are going to be away for just a few days, it may be 

better to stick to your original sleep and wake times as much as 

possible, rather than adjusting your biological clock too many 

times in rapid succession. 

Eastward travel generally causes more severe jet lag than 

westward travel because traveling east requires you to shorten 

the day, and your biological clock is better able to adjust to a 

longer day than a shorter day. Fortunately for globetrotters, a 

few preventive measures and adjustments seem to help some 

people relieve jet lag, particularly when they are going to spend 

more than a few days at their destination: 

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Adjust your biological clock. During the 2–3 days prior to a 

long trip, get adequate sleep. You can make minor changes 

to your sleep schedule. For example, if you are traveling 

west, delay your bed time and wake time progressively by 

20- to 30-minute intervals. If you are traveling east, advance 

your wake time by 10 to 15 minutes a day for a few days and 

try to advance your bed time. Decreasing light exposure 

at bedtime and increasing light exposure at wake time can 

help you make these adjustments. When you arrive at your 

destination, spend a lot of time outdoors so your body gets 

the light cues it needs to adjust to the new time zone. Take 

a couple of short 10–15 minute catnaps if you feel tired, but 

do not take long naps during the day. 

Avoid alcohol and caffeine. Although it may be tempting 

to drink alcohol to relieve the stress of travel and make it 

easier to fall asleep, you’re more likely to sleep lighter and 

wake up in the middle of the night when the effects of the 

alcohol wear off. Caffeine can help keep you awake longer, 

but caffeine also can make it harder for you to fall asleep if 

its effects haven’t worn off by the time you are ready to go 

to bed. Therefore, it’s best to use caffeine only during the 

morning and not during the afternoon. 
11 

l	 What about melatonin? Your body produces this hormone 

that may cause some drowsiness and cues the brain and 

body that it is time to fall asleep. Melatonin builds up in your 

body during the early evening and into the first 2 hours of 

your sleep period, and then its release stops in the middle of 

the night. 

Melatonin is available as an over-the-counter supplement. 

Because melatonin is considered safe when used over a 

period of days or weeks and seems to help people feel 

sleepy, it has been suggested as a treatment for jet lag. But 

melatonin’s effectiveness is controversial, and its safety 

when used over a prolonged period is unclear. Some studies 

find that taking melatonin supplements before bedtime for 

several days after arrival in a new time zone can make it 

easier to fall asleep at the proper time. Other studies find 

that melatonin does not help relieve jet lag. 

What Makes You Sleep?

Jet Lag
 
12 Your Guide to Healthy Sleep 

 

 

 

 

 

What Does Sleep Do 

for You? 

A number of aspects of your health and quality of life are linked to 

sleep, and these aspects are impaired when you are sleep deprived. 

Your Learning, Memory, and Mood 

Students who have trouble grasping new information or learning 

new skills are often advised to “sleep on it,” and that advice seems 

well founded. Recent studies reveal that people can learn a task 

better if they are well rested. They also can better remember what 

they learned if they get a good night’s sleep after learning the task 

than if they are sleep deprived. Study volunteers had to sleep at 

least 6 hours to show improvement in learning. Additionally, the 

amount of improvement was directly related to how much time they 

slept—for example, volunteers who slept 8 hours outperformed 

those who slept only 6 or 7 hours. Other studies suggest that it’s 

important to get enough rest the night before a mentally challenging 

task, rather than only sleeping for a short period or waiting to sleep 

until after the task is complete. 

Many well-known artists and scientists claim to have had creative 

insights while they slept. Mary Shelley, for example, said the idea 

for her novel Frankenstein came to her in a dream. Although it has 

not been shown that dreaming is the driving force behind innovation, one study suggests that sleep is needed for creative problemsolving. In that study, volunteers were asked to perform a memory 

task and then were tested on it 8 hours later. Those who were 

allowed to sleep for 8 hours immediately after trying the task and 

before being tested were much more likely to find a creative way of 

simplifying the task and improving their performance, compared 

with those who were awake the entire 8 hours before being tested. 

Exactly what happens during sleep to improve our learning, memory, and insight isn’t known. Experts suspect, however, that while 
13 

 

 

 

people sleep, they form or strengthen the pathways of brain cells 

needed to perform these tasks. This process may explain why sleep 

is needed for proper brain development in infants. 

Not only is a good night’s sleep required to form new learning and 

memory pathways in the brain, but also sleep is necessary for those 

pathways to work well. Several studies show that lack of sleep 

causes thinking processes to slow down. Lack of sleep also makes it 

harder to focus and pay attention. Lack of sleep can make you 

more easily confused. Studies also find that a lack of sleep leads to 

faulty decisionmaking and more risk taking. A lack of sleep slows 

down your reaction time, which is particularly important to driving 

and other tasks that require quick response. When people who lack 

sleep are tested on a driving simulator, they perform just as poorly 

as people who are drunk. (See “Crash in Bed, Not on the Road” on 

page 16.) The bottom line is: Not getting a good night’s sleep can 

be dangerous! 

Even if you don’t have a mentally or physically challenging day 

ahead of you, you should still get enough sleep to put yourself in a 

good mood. Most people report being irritable, if not downright 

unhappy, when they lack sleep. People who chronically suffer from 

a lack of sleep, either because they do not spend enough time in bed 

or because they have an untreated sleep disorder, are at greater risk 

of developing depression. One group of people who usually don’t 

get enough sleep is mothers of newborns. Some experts think 

depression after childbirth (postpartum blues) is caused, in part, by a 

lack of sleep. 

Your Heart 

Sleep gives your heart and 

vascular system a much-needed 

rest. During non-REM sleep, 

your heart rate and blood 

pressure progressively 

slow as you enter deeper 

sleep. During REM 

sleep, in response to 

dreams, your heart 

What Does Sleep Do for You? 
14 Your Guide to Healthy Sleep 

 

 

 

 

and breathing rates can rise and fall and your blood pressure can be 

variable. These changes throughout the night in blood pressure and 

heart and breathing rates seem to promote cardiovascular health. 

If you don’t get enough sleep, the nightly dip in blood pressure that 

appears to be important for good cardiovascular health may not 

occur. Failure to experience the normal dip in blood pressure during 

sleep can be related to insufficient sleep time, an untreated sleep 

disorder (for example, sleep apnea), or other factors. Some sleeprelated abnormalities may be markers of heart disease and increased 

risk of stroke. 

A lack of sleep also puts your body under stress and may trigger the 

release of more adrenaline, cortisol, and other stress hormones 

during the day. These hormones keep your blood pressure from 

dipping during sleep, which increases your risk for heart disease. 

Lack of sleep also may trigger your body to produce more of certain 

proteins thought to play a role in heart disease. For example, some 

studies find that people who repeatedly don’t get enough sleep have 

higher than normal blood levels of C-reactive protein, a sign of 

inflammation. High levels of this protein may indicate an increased 

risk for a condition called atherosclerosis, or hardening of the 

arteries. 

Your Hormones 

When you were young, your mother may have told you that you 

need to get enough sleep to grow strong and tall. She may have 

been right! Deep sleep (stage 3 non-REM sleep) triggers more 

release of growth hormone, which contributes to growth in children 

and boosts muscle mass and the repair of cells and tissues in 

children and adults. Sleep’s effect on the release of sex hormones 

also contributes to puberty and fertility. Consequently, women who 

work at night and tend to lack sleep may be at increased risk of 

miscarriage. 

Your mother also probably was right if she told you that getting a 

good night’s sleep on a regular basis would help keep you from 

getting sick and help you get better if you do get sick. During sleep, 

your body creates more cytokines—cellular hormones that help the 

immune system fight various infections. Lack of sleep can reduce 

your body’s ability to fight off common infections. Research also 

reveals that a lack of sleep can reduce the body’s response to the flu 
15 

 

vaccine. For example, sleep-deprived volunteers given the flu 

vaccine produced less than half as many flu antibodies as those who 

were well rested and given the same vaccine. 

Although lack of exercise and other factors also contribute, the 

current epidemic of diabetes and obesity seems to be related, at least 

in part, to chronically short or disrupted sleep or not sleeping during 

the night. Evidence is growing that sleep is a powerful regulator of 

appetite, energy use, and weight control. During sleep, the body’s 

production of the appetite suppressor leptin increases, and the 

appetite stimulant grehlin decreases. Studies find that the less people 

sleep, the more likely they are to be overweight or obese and prefer 

eating foods that are higher in calories and carbohydrates. People 

who report an average total sleep time of 5 hours a night, for 

example, are much more likely to become obese, compared with 

people who sleep 7–8 hours a night. 

A number of hormones released during sleep also control the body’s 

use of energy. A distinct rise and fall of blood sugar levels during 

sleep appears to be linked to sleep stages. Not sleeping at the right 

time, not getting enough sleep overall, or not enough of each stage 

of sleep disrupts this pattern. One study found that, when healthy 

young men slept only 4 hours a night for 6 nights in a row, their 

insulin and blood sugar levels matched 

those seen in people who were 

developing diabetes. Another 

study found that women who 

slept less than 7 hours a night 

were more likely to develop 

diabetes over time than 

those who slept between 

7 and 8 hours a night. 

What Does Sleep Do for You? 
16 Your Guide to Healthy Sleep 

Crash in Bed 

Not on the Road 

Most people are aware of the hazards of drunk driving. But 

driving while sleepy can be just as dangerous. Indeed, 

crashes due to sleepy drivers are as deadly as those due to 

drivers impaired by alcohol. And you don’t have to be asleep 

at the wheel to put yourself and others in danger. Both 

alcohol and a lack of sleep limit your ability to react quickly 

to a suddenly braking car, a sharp curve in the road, or other 

situations that require rapid responses. Just a few seconds’ 

delay in reaction time can be a life-or-death matter when 

driving. When people who lack sleep are tested on a driving 

simulator, they perform as badly as or worse than those who 

are drunk. The combination of alcohol and lack of sleep can 

be especially dangerous. There is increasing evidence that 

sleep deprivation and inexperience behind the wheel, both 

particularly common in adolescents, is a lethal combination. 

Of course, driving is also hazardous if you fall asleep at the 

wheel, which happens surprisingly often. One-quarter of 

the drivers surveyed in New York State reported they had 

fallen asleep at the wheel at some time. Often, people briefly 

nod off at the wheel without being aware of it—they just 

can’t recall what happened over the previous few seconds 

or longer. And people who lack sleep are more apt to take 

risks and make poor judgments, which also can boost their 

chances of getting in a car crash. 

Opening a window or turning up the radio won’t help you 

stay awake while driving. The bottom line is that there is no 

substitute for sleep. Be aware of these warning signs that 

you are too sleepy to drive safely: trouble keeping your eyes 

open or focused, continual yawning, or being unable to recall 

driving the past few miles. Remember, if you are short on 

sleep, stay out of the driver’s seat! 
17 

Here are some potentially life-saving tips for avoiding drowsy 

driving: 

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Be well rested before hitting the road. If you have 

several nights in a row of fewer than 7–8 hours of sleep, 

your reaction time slows. Restoring that reaction time 

to normal can take more than one night of good sleep, 

because a sleep debt accumulates after each night you 

lose sleep. It may take several nights of being well rested 

to repay that sleep debt and make you ready for driving on 

a long road trip. 

Avoid driving between midnight and 7 a.m. Unless you 

are accustomed to being awake then, this period of time is 

when we are naturally the least alert and most tired. 

Don’t drive alone. A companion who can keep you 

engaged in conversation might help you stay awake while 

driving. 

Schedule frequent breaks on long road trips. If you feel 

sleepy while driving, pull off the road and take a nap for 

15–20 minutes. 

Don’t drink alcohol. Just one beer when you are sleep 

deprived will affect you as much as two or three beers 

when you are well rested. 

Don’t count on caffeine or other tricks. Although 

drinking a cola or a cup of coffee might help keep you 

awake for a short time, it won’t overcome extreme 

sleepiness or relieve a sleep debt. 

What Does Sleep Do for You? 
18 Your Guide to Healthy Sleep 

I wake up early to get ready for school. 

I am tired in the morning, and by the end 

of the school day, I am very tired again. An 

afterschool nap seems to refresh me and 

help me focus on homework. Without it, 

I am grumpy and stressed, can’t focus, and 

sometimes get headaches.

DAPHNE 

“ 

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19 

 

 

 

 

 

 

 

How Much Sleep Is 

Enough? 

Animal studies suggest that sleep is as vital as food for survival. 

Rats, for example, normally live 2–3 years, but they live only 

5 weeks if they are deprived of REM sleep and only 2–3 weeks if 

they are deprived of all sleep stages—a timeframe similar to death 

due to starvation. But how much sleep do humans need? To help 

answer that question, scientists look at how much people sleep when 

unrestricted, the average amount of sleep among various age groups, 

and the amount of sleep that studies reveal is necessary to function 

at your best. 

When healthy adults are given unlimited opportunity to sleep, they 

sleep on average between 8 and 8.5 hours a night. But sleep needs 

vary from person to person. Some people appear to need only about 

7 hours to avoid problem sleepiness, whereas others need 9 or more 

hours of sleep. Sleep needs also change throughout the life cycle. 

Newborns sleep between 16 and 18 hours a day, and children in 

preschool sleep between 11 and 12 hours a day. School-aged 

children and adolescents need at least 10 hours of sleep each night. 

The hormonal influences of puberty tend to shift adolescents’ biological clocks. As a result, teenagers (who need between 9 and 10 hours 

of sleep a night) are more likely to go to bed later than younger 

children and adults, and they tend to want to sleep later in the 

morning. This delayed sleep–wake rhythm conflicts with the earlymorning start times of many high schools and helps explain why 

most teenagers get an average of only 7–7.5 hours of sleep a night. 

As people get older, the pattern of sleep also changes—especially the 

amount of time spent in deep sleep. This explains why children can 

sleep through loud noises and why they might not wake up when 

moved. Across the lifespan, the sleep period tends to advance, 

namely relative to teenagers; older adults tend to go to bed earlier 

and wake earlier. The quality—but not necessarily the quantity—of 

How Much Sleep Is Enough? 
20 Your Guide to Healthy Sleep 

 

 

deep, non-REM sleep also changes, with a trend toward lighter 

sleep. The relative percentages of stages of sleep appear to stay 

mostly constant after infancy. From midlife through late life, people 

awaken more throughout the night. These sleep disruptions cause 

older people to lose more and more of stages 1 and 2 non-REM 

sleep as well as REM sleep. 

Some older people complain of difficulty falling asleep, early 

morning awakenings, frequent and long awakenings during the 

night, daytime sleepiness, and a lack of refreshing sleep. Many sleep 

problems, however, are not a natural part of 

sleep in the elderly. Their sleep complaints 

may be due, in part, to medical conditions, 

illnesses, or medications they are taking—

all of which can disrupt sleep. In fact, one 

study found that the prevalence of sleep 

problems is very low in healthy older adults. 

Other causes of some of older adults’ 

sleep complaints are sleep apnea, restless 

legs syndrome, and other sleep disorders 

that become more common with age. 

Also, older people are more likely to 

have their sleep disrupted by the need 

to urinate during the night. 

Some evidence shows that the 

biological clock shifts in older 

people, so they are more apt to go to 

sleep earlier at night and wake up 

earlier in the morning. No evidence 

indicates that older people can get 

by with less sleep than younger 

people. (See “Top 10 Sleep Myths” 

on page 22.) Poor sleep in older 

people may result in excessive 

daytime sleepiness, attention 

and memory problems, depressed 

mood, and overuse of sleeping pills. 

Despite variations in sleep quantity 

and quality, both related to age and 
21 

 

 

between individuals, studies suggest that the optimal amount of 

sleep needed to perform adequately, avoid a sleep debt, and not have 

problem sleepiness during the day is about 7–8 hours for adults and 

at least 10 hours for school-aged children and adolescents. Similar 

amounts seem to be necessary to avoid an increased risk of developing obesity, diabetes, or cardiovascular diseases. 

Quality of sleep and the timing of sleep are as important as quantity. 

People whose sleep is frequently interrupted or cut short may not get 

enough of both non-REM sleep and REM sleep. Both types of sleep 

appear to be crucial for learning and memory—and perhaps for the 

restorative benefits of healthy sleep, including the growth and repair 

of cells. 

Many people try to make up for lost sleep during the week by 

sleeping more on the weekends. But if you have lost too much sleep, 

sleeping in on a weekend does not completely erase your sleep debt. 

Certainly, sleeping more at the end of a week won’t make up for any 

poor performance you had earlier in that week. Just one night of 

inadequate sleep can negatively affect your functioning and mood 

during at least the next day. 

Daytime naps are another strategy some people use to make up for 

lost sleep during the night. Some evidence shows that 

short naps (up to an hour) can make up, at least 

partially, for the sleep missed on the previous 

night and improve alertness, mood, and work 

performance. But naps don’t substitute for a 

good night’s sleep. One study found that a 

daytime nap after a lack of sleep at night did 

not fully restore levels of blood sugar to the 

pattern seen with adequate nighttime 

sleep. If a nap lasts longer than 

20 minutes, you may have a hard 

time waking up fully. 

In addition, late afternoon 

naps can make falling asleep 

at night more difficult. 

How Much Sleep Is Enough? 
22 Your Guide to Healthy Sleep 

Top 10

 Sleep Myths

Myth 1: Sleep is a time when your body and brain shut down 

for rest and relaxation. No evidence shows that any major 

organ (including the brain) or regulatory system in the body shuts 

down during sleep. Some physiological processes actually 

become more active while you sleep. For example, secretion of 

certain hormones is boosted, and activity of the pathways in the 

brain linked to learning and memory increases. 

Myth 2: Getting just 1 hour less sleep per night than needed 

will not have any effect on your daytime functioning. This 

lack of sleep may not make you noticeably sleepy during 

the day. But even slightly less sleep can affect your ability 

to think properly and respond quickly, and it can impair your 

cardiovascular health and energy balance as well as your body’s 

ability to fight infections, particularly if lack of sleep continues. If 

you consistently do not get enough sleep, a sleep debt builds up 

that you can never repay. This sleep debt affects your health and 

quality of life and makes you feel tired during the day. 

Myth 3: Your body adjusts quickly to different sleep 

schedules. Your biological clock makes you most alert during 

the daytime and least alert at night. Thus, even if you work 

the night shift, you will naturally feel sleepy when nighttime 

comes. Most people can reset their biological clock, but only by 

appropriately timed cues—and even then, by 1–2 hours per day 

at best. Consequently, it can take more than a week to adjust 

to a substantial change in your sleep–wake cycle—for example, 

when traveling across several time zones or switching from 

working the day shift to the night shift. 

Myth 4: People need less sleep as they get older. Older 

people don’t need less sleep, but they may get less sleep or find 

their sleep less refreshing. That’s because as people age, the 

quality of their sleep changes. Older people are also more 

likely to have insomnia or other medical conditions that disrupt 

their sleep. 
23 

Myth 5: Extra sleep for one night can cure you of problems 

with excessive daytime fatigue. Not only is the quantity of 

sleep important, but also the quality of sleep. Some people 

sleep 8 or 9 hours a night but don’t feel well rested when they 

wake up because the quality of their sleep is poor. A number of 

sleep disorders and other medical conditions affect the quality 

of sleep. Sleeping more won’t lessen the daytime sleepiness 

these disorders or conditions cause. However, many of these 

disorders or conditions can be treated effectively with changes 

in behavior or with medical therapies. Additionally, one night of 

increased sleep may not correct multiple nights of inadequate 

sleep. 

Myth 6: You can make up for lost sleep during the week 

by sleeping more on the weekends. Although this sleeping 

pattern will help you feel more rested, it will not completely 

make up for the lack of sleep or correct your sleep debt. 

This pattern also will not necessarily make up for impaired 

performance during the week or the physical problems that can 

result from not sleeping enough. Furthermore, sleeping later on 

the weekends can affect your biological clock, making it much 

harder to go to sleep at the right time on Sunday nights and get 

up early on Monday mornings. 

Myth 7: Naps are a waste of time. Although naps are no 

substitute for a good night’s sleep, they 

can be restorative and help counter 

some of the effects of not getting 

enough sleep at night. Naps can 

actually help you learn how to do 

certain tasks quicker. But avoid 

taking naps later than 3 p.m., 

particularly if you have trouble falling 

asleep at night, as late naps can make 

it harder for you to fall asleep 

when you go to bed. Also, 

limit your naps to no 

longer than 20 minutes, 

because longer naps 

will make it harder 

to wake up and 

How Much Sleep Is Enough? 
24 Your Guide to Healthy Sleep 

Top 10 

 Sleep Myths (continued) 

get back in the swing of things. If you take more than one or 

two planned or unplanned naps during the day, you may have a 

sleep disorder that should be treated. 

Myth 8: Snoring is a normal part of sleep. Snoring during 

sleep is common, particularly as a person gets older. Evidence 

is growing that snoring on a regular basis can make you sleepy 

during the day and increase your risk for diabetes and heart 

disease. In addition, some studies link frequent snoring to 

problem behavior and poorer school achievement in children. 

Loud, frequent snoring also can be a sign of sleep apnea, a 

serious sleep disorder that should be evaluated and treated. 

(See “Is Snoring a Problem?” on page 30.) 

Myth 9: Children who don’t get enough sleep at night will 

show signs of sleepiness during the day. Unlike adults, 

children who don’t get enough sleep at night typically become 

hyperactive, irritable, and inattentive during the day. They also 

have increased risk of injury and more behavior problems, and 

their growth rate may be impaired. Sleep debt appears to be 

quite common during childhood and may be misdiagnosed as 

attention-deficit hyperactivity disorder. 

Myth 10: The main cause of insomnia is worry. Although 

worry or stress can cause a short bout of insomnia, a persistent 

inability to fall asleep or stay asleep at night can be caused 

by a number of other factors. Certain medications and sleep 

disorders can keep you up at night. Other common causes of 

insomnia are depression, anxiety disorders, and asthma, arthritis, 

or other medical conditions with symptoms that tend to be 

troublesome at night. Some people who have chronic insomnia 

also appear to be more “revved up” than normal, so it is harder 

for them to fall asleep. 

Sleep Myths
 
25 

 

 

 

 

 

 

 

When medicines didn’t 

work for me, I started 

making big lifestyle 

changes. Now I try to 

eat a balanced diet and 

walk for at least an hour 

each day. Without doubt, 

my weight loss and more 

active lifestyle help me 

sleep better.

What Disrupts Sleep?
 

Many factors can prevent a good night’s sleep. These factors range 

from well-known stimulants, such as coffee, to certain pain relievers, 

decongestants, and other culprits. Many people depend on the 

caffeine in coffee, cola, or tea to wake them up in the morning or to 

keep them awake. Caffeine is thought to block the cell receptors 

that adenosine (a substance in the brain) uses to trigger its sleepinducing signals. In this way, caffeine fools the body into thinking it 

isn’t tired. It can take as long as 6–8 hours for the effects of caffeine 

to wear off completely. Thus, drinking a cup of coffee in the late 

afternoon may prevent your falling asleep at night. 

Nicotine is another stimulant that can keep you awake. Nicotine 

also leads to lighter than normal sleep, and heavy smokers tend to 

wake up too early because of nicotine withdrawal. Although 

alcohol is a sedative that makes it easier to fall asleep, it prevents 

deep sleep and REM sleep, allowing only the lighter stages of sleep. 

People who drink alcohol also tend to wake up in the middle of the 

night when the effects of an alcoholic “nightcap” wear off. 

Certain commonly used prescription and over-the-counter medicines contain ingredients that can 

keep you awake. These ingredients 

include decongestants and steroids. 

Many medicines taken to relieve 

headaches contain caffeine. Heart 

and blood pressure medications 

known as beta blockers can make 

it difficult to fall asleep and cause 

more awakenings during the night. 

People who have chronic asthma 

or bronchitis also have more 

problems falling asleep and staying 

asleep than healthy people, either 

because of their breathing difficulties or because of the medicines 

What Disrupts Sleep? 

SZE-PING 

“ 

” 
26 Your Guide to Healthy Sleep 

 

 

 

 

 

they take. Other chronic painful or uncomfortable conditions— 

such as arthritis, congestive heart failure, and sickle cell anemia— 

can disrupt sleep, too. 

A number of psychological disorders—including schizophrenia, 

bipolar disorder, and anxiety disorders—are well known for disrupting sleep. Depression often leads to insomnia, and insomnia can 

cause depression. Some of these psychological disorders are more 

likely to disrupt REM sleep. Psychological stress also takes its toll 

on sleep, making it more difficult to fall asleep or stay asleep. 

People who feel stressed also tend to spend less time in deep sleep 

and REM sleep. Many people report having difficulties sleeping if, 

for example, they have recently lost a loved one, are going through a 

divorce, or are under stress at work. 

Menstrual cycle hormones can affect how well women sleep. Progesterone is known to induce sleep and circulates in greater concentrations in the second half of the menstrual cycle. For this reason, 

women may sleep better during this phase of their menstrual cycle. 

On the other hand, many women report trouble sleeping the night 

before their menstrual flow starts. This sleep disruption may be 

related to the abrupt drop in progesterone levels that occurs just 

before menstruation. Women in their late forties and early fifties, 

however, report more difficulties sleeping (insomnia) than younger 

women. These difficulties may be linked to menopause, when they 

have lower concentrations of progesterone. Hot flashes in women 

of this age also may cause sleep disruption and difficulties. 

Certain lifestyle factors also may deprive a person 

of needed sleep. Large meals or vigorous 

exercise just before bedtime can make it 

harder to fall asleep. While vigorous exercise 

in the evening may delay sleep onset for 

various reasons, exercise in the daytime is 

associated with improved nighttime sleep. 

If you aren’t getting enough sleep 

or aren’t falling asleep early 

enough, you may be 

overscheduling activities that can prevent you from 

getting the 
27 

 

quiet relaxation time you need to prepare for sleep. Most people 

report that it’s easier to fall asleep if they have time to wind down 

into a less active state before sleeping. Relaxing in a hot bath or 

having a hot, caffeine-free beverage before bedtime may help. In 

addition, your body temperature drops after a hot bath in a way 

that mimics, in part, what happens as you fall asleep. Probably for 

both these reasons, many people report that they fall asleep more 

easily after a hot bath. 

Your sleeping environment also can affect your sleep. Clear your 

bedroom of any potential sleep distractions, such as noises, bright 

lights, a TV, a cell phone, or computer. Having a comfortable 

mattress and pillow can help promote a good night’s sleep. You also 

sleep better if the temperature in your bedroom is kept on the cool 

side. For more ideas on improving your sleep, check out the tips for 

getting a good night’s sleep below. 

Tips for Getting a
 

 Good Night’s Sleep

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l

Stick to a sleep schedule. Go to bed and wake up at the 

same time each day. As creatures of habit, people have a 

hard time adjusting to changes in sleep patterns. Sleeping 

later on weekends won’t fully make up for a lack of sleep 

during the week and will make it harder to wake up early on 

Monday morning. 

Exercise is great, but not too late in the day. Try to 

exercise at least 30 minutes on most days but not later than 

2–3 hours before your bedtime. 

Avoid caffeine and nicotine. Coffee, colas, certain teas, 

and chocolate contain the stimulant caffeine, and its effects 

can take as long as 8 hours to wear off fully. Therefore, a 

cup of coffee in the late afternoon can make it hard for you 

to fall asleep at night. Nicotine is also a stimulant, often 

causing smokers to sleep only very lightly. In addition, 

smokers often wake up too early in the morning because of 

nicotine withdrawal. 

What Disrupts Sleep? 
28 Your Guide to Healthy Sleep 

Tips for Getting a 

 Good Night’s Sleep (continued) 

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Avoid alcoholic drinks before bed. Having a “nightcap” or 

alcoholic beverage before sleep may help you relax, but heavy 

use robs you of deep sleep and REM sleep, keeping you in 

the lighter stages of sleep. Heavy alcohol ingestion also may 

contribute to impairment in breathing at night. You also tend 

to wake up in the middle of the night when the effects of the 

alcohol have worn off. 

Avoid large meals and beverages late at night. A light snack 

is okay, but a large meal can cause indigestion that interferes 

with sleep. Drinking too many fluids at night can cause 

frequent awakenings to urinate. 

If possible, avoid medicines that delay or disrupt your 

sleep. Some commonly prescribed heart, blood pressure, or 

asthma medications, as well as some over-the-counter and 

herbal remedies for coughs, colds, or allergies, can disrupt 

sleep patterns. If you have trouble sleeping, talk to your doctor 

or pharmacist to see whether any drugs you’re taking might 

be contributing to your insomnia and ask whether they can be 

taken at other times during the day or early in the evening. 

Don’t take naps after 3 p.m. Naps can help make up for lost 

sleep, but late afternoon naps can make it harder to fall asleep 

at night. 

Relax before bed. Don’t overschedule your day so that no 

time is left for unwinding. A relaxing activity, such as reading or 

listening to music, should be part of your bedtime ritual. 

Take a hot bath before bed. The drop in body temperature 

after getting out of the bath may help you feel sleepy, and the 

bath can help you relax and slow down so you’re more ready to 

sleep. 

Have a good sleeping environment. Get rid of anything 

in your bedroom that might distract you from sleep, such 

as noises, bright lights, an uncomfortable bed, or warm 

temperatures. You sleep better if the temperature in the room 
29 

is kept on the cool side. A TV, cell phone, or computer in the 

bedroom can be a distraction and deprive you of needed sleep. 

Having a comfortable mattress and pillow can help promote a 

good night’s sleep. Individuals who have insomnia often watch 

the clock. Turn the clock’s face out of view so you don’t worry 

about the time while trying to fall asleep. 

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Have the right sunlight exposure. Daylight is key to 

regulating daily sleep patterns. Try to get outside in natural 

sunlight for at least 30 minutes each day. If possible, wake 

up with the sun or use very bright lights in the morning. Sleep 

experts recommend that, if you have problems falling asleep, 

you should get an hour of exposure to morning sunlight and 

turn down the lights before bedtime. 

Don’t lie in bed awake. If you find yourself still awake after 

staying in bed for more than 20 minutes or if you are starting 

to feel anxious or worried, get up and do some relaxing 

activity until you feel sleepy. The anxiety of not being able to 

sleep can make it harder to 

fall asleep. 

See a doctor if you 

continue to have 

trouble sleeping. If you 

consistently find it difficult 

to fall or stay asleep and/ 

or feel tired or not well 

rested during the day 

despite spending enough 

time in bed at night, you 

may have a sleep disorder. 

Your family doctor or a 

sleep specialist should 

be able to help you, and 

it is important to rule out 

other health or psychiatric 

problems that may be 

disturbing your sleep. 

What Disrupts Sleep? 
30 

 

 

 

 

 

 

My wife noticed that 

I snored loudly and 

sometimes stopped 

breathing in the middle 

of the night. She was the 

one who finally pushed me 

to see a doctor.

Is Snoring a Problem?
 

Long the material for jokes, snoring is generally accepted as common and annoying in adults but as nothing to worry about. However, snoring is no laughing matter. Frequent, loud snoring is often a 

sign of sleep apnea and may increase your risk of developing cardiovascular disease and diabetes. Snoring also may lead to daytime 

sleepiness and impaired performance. 

Snoring is caused by a narrowing or partial blockage of the airways 

at the back of your mouth, throat, or nose. This obstruction results 

in increased air turbulence when breathing in, causing the soft 

tissues in your upper airways to vibrate. The end result is a noisy 

snore that can disrupt the sleep of your bed partner. This narrowing 

of the airways is typically caused by the soft palate, tongue, and 

throat relaxing while you sleep, but allergies or sinus problems also 

can contribute to a narrowing of the airways, as can being overweight and having extra soft tissue around your upper airways. 

The larger the tissues in your soft palate (the roof of your mouth in 

the back of your throat), the more likely you are to snore while 

sleeping. Alcohol or sedatives taken shortly before sleep also 

promote snoring. These drugs cause greater relaxation of the tissues 

Your Guide to Healthy Sleep 

in your throat and mouth. Surveys 

reveal that about one-half of all 

adults snore, and 50 percent of 

these adults do so loudly and 

frequently. African Americans, 

Asians, and Hispanics are more 

likely to snore loudly and frequently compared with Caucasians, 

and snoring problems increase 

with age. 

Not everyone who snores has sleep 

apnea, but people who have sleep 

apnea typically do snore loudly 

and frequently. Sleep apnea is a 

JIM

“ 

” 
31 

 

 

 

 

 

 

 

 

serious sleep disorder, and its hallmark is loud, frequent snoring 

with pauses in breathing or shallow breaths while sleeping. (See 

“Sleep Apnea” on page 38.) Even if you don’t experience these 

breathing pauses, snoring can still be a problem for you as well as 

for your bed partner. Snoring adds extra effort to your breathing, 

which can reduce the quality of your sleep and lead to many of the 

same health consequences as sleep apnea. 

One study found that older adults who did not have sleep apnea, 

but who snored 6–7 nights a week, were more than twice as likely to 

report being extremely sleepy during the day than those who never 

snored. The more people snored, the more daytime fatigue they 

reported. That sleepiness may help explain why snorers are more 

likely to be in car crashes than people who don’t snore. Loud 

snoring also can disrupt the sleep of bed partners and strain marital 

relations, especially if snoring causes the spouses to sleep in separate 

bedrooms. 

In addition, snoring increases the risk of developing diabetes and 

heart disease. One study found that women who snored regularly 

were twice as likely as those who did not snore to develop diabetes, 

even if they were not overweight (another risk factor for diabetes). 

Other studies suggest that regular snoring may raise the lifetime risk 

of developing high blood pressure, heart failure, and stroke. 

About one-third of all pregnant women begin snoring for the first 

time during their second trimester. If you are snoring while pregnant, let your doctor know. Snoring in pregnancy can be associated 

with high blood pressure and can have a negative effect on your 

baby’s growth and development. Your doctor will keep a close eye 

on your blood pressure throughout your pregnancy and can let you 

know if any additional evaluations for the snoring might be useful. 

In most cases, the snoring and any related high blood pressure will 

go away shortly after delivery. 

Snoring also can be a problem in children. As many as 10–15 percent of young children, who typically have enlarged adenoids and 

tonsils (both tissues in the throat), snore on a regular basis. Several 

studies show that children who snore (with or without sleep apnea) 

are more likely than those who do not snore to score lower on tests 

that measure intelligence, memory, and attention span. These 

children also have more problematic behavior, including hyperactivity. The end result is that children who snore don’t perform in 

Is Snoring a Problem? 
32 Your Guide to Healthy Sleep 

 

 

 

 

 

school as well as those who do not snore. Strikingly, snoring was 

linked to a greater drop in IQ than that seen in children who had 

elevated levels of lead in their blood. Although the behavior of 

children improves after they stop snoring, studies suggest they may 

continue to get poorer grades in school, perhaps because of lasting 

effects on the brain linked to the snoring. You should have your 

child evaluated by your doctor if the child snores loudly and 

frequently—three to four times a week—especially if you note brief 

pauses in breathing while asleep and if there are signs of hyperactivity or daytime sleepiness, inadequate school achievement, or slower 

than expected development. 

Surgery to remove the adenoids and tonsils of children often can 

cure their snoring and any associated sleep apnea. Such surgery has 

been linked to a reduction in hyperactivity and improved ability to 

pay attention, even in children who showed no signs of sleep apnea 

before surgery. 

Snoring in older children and adults may be relieved by less invasive 

measures, however. These measures include losing weight, refraining 

from use of tobacco, sleeping on the side rather than on the back, or 

elevating the head while sleeping. Treating chronic congestion and 

refraining from alcohol or sedatives before sleeping also may decrease snoring. In some adults, snoring can be relieved by dental 

appliances that reposition the soft tissues in the mouth. Although 

numerous over-the-counter nasal strips and sprays claim to relieve 

snoring, no scientific evidence supports those claims. 
33 

Common Sleep Disorders
 

A number of sleep disorders can disrupt your sleep quality and make 

you overly sleepy during the day, even if you spent enough time in 

bed to be well rested. (See “Common Signs of a Sleep Disorder” on 

page 34.) 

Common Sleep Disorders 

More than 70 sleep disorders affect at least 40 million Americans 

and account for an estimated $16 billion in medical costs each year, 

not counting costs due to lost work time, car 

accidents, and other factors. 

The four most common sleep disorders 

are insomnia, sleep apnea, restless legs 

syndrome, and narcolepsy. Additional 

sleep problems include chronic 

insufficient sleep, circadian rhythm 

abnormalities, and “parasomnias” 

such as sleep walking, sleep paralysis, 

and night terrors. 

LAUREN

“

My restless legs syndrome 

made me lose sleep and 

affected my quality of life. 

But I’m in a good place 

right now. I’m taking the 

right medicine for me, and 

I’ve adopted a healthy, 

active lifestyle. I am 

very passionate 

about taking control 

of my health.” 
34 Your Guide to Healthy Sleep 

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Common Signs of a

 Sleep disorder

Look over this list of common signs of a sleep disorder, and talk 

to your doctor if you have any of them on three or more nights a 

week: 

It takes you more than 30 minutes to fall asleep at night. 

You awaken frequently in the night and then have trouble 

falling back to sleep again. 

You awaken too early in the morning. 

You often don’t feel well rested despite spending 7–8 hours or 

more asleep at night. 

You feel sleepy during the day and fall asleep within 

5 minutes if you have an opportunity to nap, or you fall 

asleep unexpectedly or at inappropriate times during the day. 

Your bed partner claims you snore loudly, snort, gasp, or 

make choking sounds while you sleep, or your partner notices 

that your breathing stops for short periods. 

You have creeping, tingling, or crawling feelings in your legs 

that are relieved by moving or massaging them, especially in 

the evening and when you try to fall asleep. 

You have vivid, dreamlike experiences while falling asleep 

or dozing. 

You have episodes of sudden muscle weakness when you are 

angry or fearful, or when you laugh. 

You feel as though you cannot move when you first wake up. 

Your bed partner notes that your legs or arms jerk often 

during sleep. 

You regularly need to use stimulants to stay awake during 

the day. 

Also keep in mind that, although children can show some of 

these signs of a sleep disorder, they often do not show signs 

of excessive daytime sleepiness. Instead, they may seem 

overactive and have difficulty focusing and concentrating. 

They also may not do their best in school. 
35 

 

 

 

 

 

n	 

n	 

Insomnia 

Insomnia is defined as having trouble falling asleep or staying asleep, 

or as having unrefreshing sleep despite having ample opportunity to 

sleep. Life is filled with events that occasionally cause insomnia for 

a short time. Such temporary insomnia is common and is often 

brought on by situations such as stress at work, family pressures, or 

a traumatic event. A National Sleep Foundation poll of adults in the 

United States found that close to half of the respondents reported 

temporary insomnia in the nights immediately after the terrorist 

attacks on September 11, 2001. 

Chronic insomnia is defined as having symptoms at least 3 nights 

per week for more than 1 month. Most cases of chronic insomnia 

are secondary, which means they are due to another disorder or 

medications. Primary chronic insomnia is a distinct sleep disorder; 

its cause is not yet well understood. About 30–40 percent of adults 

say they have some symptoms of insomnia within any given year, 

and about 10–15 percent of adults say they have chronic insomnia. 

Chronic insomnia becomes more common with age, and women are 

more likely than men to report having insomnia. 

Insomnia often causes problems during the day, such as extreme 

sleepiness, fatigue, a lack of energy, difficulty concentrating, 

depressed mood, and irritability. Thus, untreated insomnia can 

impair quality of life as much as, or more than, other chronic 

medical problems. 

Chronic insomnia is often caused by one or more of the following: 

A disease or mood disorder. The most common causes of 

insomnia are depression and/or anxiety disorders. Neurological disorders, such as Alzheimer’s or Parkinson’s disease, 

also can have insomnia as a symptom. Chronic insomnia can 

result from thyroid dysfunction, arthritis, asthma, or other 

medical conditions in which symptoms become more troublesome at night, making it difficult to fall asleep or stay asleep. 

Various prescribed and over-the-counter medications that can 

disrupt sleep, such as decongestants, certain pain relievers, 

and steroids. 

Common Sleep Disorders 
36 Your Guide to Healthy Sleep 

n	 

n	 

 

 

 

 

 

 

Sleep-disrupting behavior such as drinking alcohol, exercising 

shortly before bedtime, ingesting caffeine late in the day, 

watching TV or reading while in bed, or irregular sleep 

schedules due to shift work or other causes. 

Another sleep disorder, such as sleep apnea or restless legs 

syndrome. 

Some people, however, have primary chronic insomnia. This condition is linked to a tendency to be more “revved up” than normal 

(hyperarousal). People who have primary chronic insomnia may 

have heightened levels of certain hormones, higher body temperatures, faster heart rates, and a different pattern of brain waves while 

they sleep. 

Doctors diagnose insomnia based mainly on sleep history, often by 

reviewing a sleep diary. An overnight sleep recording may be 

required if another sleep disorder is suspected. Doctors also will try 

to diagnose and treat any other underlying medical or psychological 

problems as well as identify behaviors that might be causing the 

insomnia. 

Often, people who have insomnia enter into a vicious cycle—because 

they’ve had trouble sleeping on previous nights, they become anxious 

at the slightest sign that they may not be falling asleep right away. 

That anxiety can make it more difficult for them to fall asleep. The 

more time they spend in bed not sleeping, and watching the clock, 

the more their anxiety—and sleeplessness—increases. 

To break that cycle of anxiety and negative conditioning, experts 

recommend going to bed only when you’re sleepy. If you can’t fall 

asleep (or fall back to sleep) within 20 minutes, get out of bed, go 

into another room, and do a relaxing activity (such as reading) until 

you feel sleepy again. Then return to bed. Studies have shown that 

this reconditioning therapy is an effective way to treat insomnia. 

Relaxation therapy is another strategy that works for some people 

who have insomnia. Relaxation therapy may include meditation 

and other mental relaxation techniques. It also may include physical 

relaxation techniques, such as progressively tensing and then relaxing each of the muscle groups in your body before sleep. Another 

method is to focus on breathing deeply. Relaxation therapy can help 

your body and mind slow down so that you can fall asleep more 

easily at bedtime. 
37 

 

 

 

Sleep restriction therapy also works for some people who have 

insomnia. Calculate your average sleep time over the course of a 

week, and then limit your nightly sleep time to that average. Gradually add more sleep time each night until you achieve a more normal 

night’s sleep. You should avoid daytime naps longer than 15–20 minutes during sleep restriction therapy. Napping can make it harder to 

fall asleep at night, which may prolong insomnia. In addition, during 

sleep restriction therapy, avoid driving a car or operating dangerous 

machinery until you are getting enough sleep at night. 

All of these behavioral changes are part of a treatment called 

cognitive behavioral therapy. Cognitive behavioral therapy also can 

be used to replace negative thoughts about sleep, such as “I’ll never 

fall asleep without sleeping pills,” with more realistic positive 

thinking. Cognitive behavioral therapy is effective in most people 

who have chronic insomnia. 

Some people who have chronic insomnia that is not corrected by 

behavioral therapy or treatment of an underlying condition 

may need a prescription medication. You should talk to a doctor 

before trying to treat insomnia with alcohol, over-the-counter or 

prescribed short-acting sedatives, or sedating 

antihistamines that induce drowsiness. 

The benefits of these treatments are 

limited, and they have risks. Some 

may help you fall asleep but leave you 

feeling unrefreshed in the morning. 

Others have longer lasting effects and 

leave you feeling still tired and groggy 

in the morning. Some also may lose 

their effectiveness over time. 

Doctors may prescribe sedating 

antidepressants for insomnia, 

but the effectiveness of these 

medicines in people who do 

not have depression is not 

known, and there are 

significant side effects. 

Common Sleep Disorders 
38 Your Guide to Healthy Sleep 

 

 

 

 

 

 

 

 

To treat their insomnia, some people pursue “natural” remedies, 

such as melatonin supplements or valerian teas or extracts. These 

remedies are available over the counter. Little evidence exists that 

melatonin can help relieve insomnia. Studies with valerian also have 

been inconclusive, and the actual dose and purity of various 

supplements, extracts, or teas that contain valerian may vary from 

product to product. In addition, because melatonin, valerian, and 

other natural remedies are not regulated by the Food and Drug 

Administration, their safety is not monitored. 

Sleep Apnea 

In people who have sleep apnea (also referred to as sleep-disordered 

breathing), breathing briefly stops or becomes very shallow during 

sleep. This change is caused by intermittent blocking of the upper 

airway, usually when the soft tissue in the rear of the throat 

collapses and partially or completely closes the airway. Each pause 

in breathing typically lasts 10–120 seconds and may occur 20–30 

times or more each sleeping hour. 

If you have sleep apnea, not enough air can flow into your lungs 

through your mouth and nose during sleep, even though breathing 

efforts continue. When this happens, the amount of oxygen in your 

blood decreases. Your brain responds by awakening you enough to 

tighten the upper airway muscles and open your windpipe. Normal 

breaths then start again, often with a loud snort or choking sound. 

Although people who have sleep apnea typically snore loudly and 

frequently, not everyone who snores has sleep apnea. (See “Is 

Snoring a Problem?” on page 30.) 

Because people who have sleep apnea frequently go from deeper 

sleep to lighter sleep during the night, they rarely spend enough time 

in deep, restorative stages of sleep. They are therefore often excessively sleepy during the day. Such sleepiness is thought to lead to 

mood and behavior problems, including depression, and it more 

than triples the risk of being in a traffic or work-related accident. 

The many brief drops in blood-oxygen levels that occur during the 

night can result in morning headaches and trouble concentrating, 

thinking clearly, learning, and remembering. Additionally, the 

intermittent oxygen drops and reduced sleep quality together trigger 

the release of stress hormones. These hormones raise your blood 

pressure and heart rate and boost the risk of heart attack, stroke, 

irregular heartbeats, and congestive heart failure. In addition, 
39 Common Sleep Disorders 

I realize now that my sleep apnea 

affected my quality of life. I felt tired 

all the time—so tired that I couldn’t 

exercise or spend time with my kids. 

I had other sleep apnea symptoms 

that affected my work—headaches, 

confusion, making errors, etc.

“Looking back, I know 

that I should have taken 

it more seriously and 

told my doctor about my 

symptoms many years 

before I did.

“One thing that helps me is 

physical activity. Now that 

I am feeling better, I come 

home from work with 

enough energy to have an 

exercise routine.

JIM

“ 

” 
40 Your Guide to Healthy Sleep 

untreated sleep apnea can lead to changes in energy metabolism (the 

way your body changes food and oxygen into energy) that increase 

the risk for developing obesity and diabetes. 

Anyone can have sleep apnea. It is estimated that at least 12–18 

million American adults have sleep apnea, making it as common as 

asthma. More than one-half of the people who have sleep apnea are 

overweight. Sleep apnea is more common in men. More than 1 in 

25 middle-aged men and 1 in 50 middle-aged women have sleep 

apnea along with extreme daytime sleepiness. About 3 percent of 

children and 10 percent or more of people over age 65 have sleep 

apnea. This condition occurs more frequently in African Americans, 

Asians, Native Americans, and Hispanics than in Caucasians. 

More than one-half of all people who have sleep apnea are not 

diagnosed. People who have sleep apnea generally are not aware 

that their breathing stops in the night. They just notice that they 

don’t feel well rested when they wake up and are sleepy throughout 

the day. Their bed partners are likely to notice, however, that they 

snore loudly and frequently and that they 

often stop breathing briefly while 

sleeping. Doctors suspect sleep apnea 

if these symptoms are present, but 

the diagnosis must be confirmed 

with overnight sleep monitoring. 

(See “How Are Sleep Disorders 

Diagnosed?” on page 44.) This 

monitoring will reveal pauses in 

breathing, frequent sleep 

arousals (changes from 

sleep to wakefulness), and 

intermittent drops in 

levels of oxygen in 

the blood. 
41 

 

 

 

 

n	 

n	 

n	 

n	 

Like adults who have sleep apnea, children who have this disorder 

usually snore loudly, snort or gasp, and have brief pauses in breathing while sleeping. Small children often have enlarged tonsils and 

adenoids that increase their risk for sleep apnea. But doctors may 

not suspect sleep apnea in children because, instead of showing the 

typical signs of sleepiness during the day, these children often 

become agitated and may be considered hyperactive. The effects of 

sleep apnea in children may include poor school performance and 

difficult, aggressive behavior. 

A number of factors can make a person susceptible to sleep apnea. 

These factors include: 

n

n

n

n

n

n

Throat muscles and tongue that relax more than normal while 

asleep 

Enlarged tonsils and adenoids 

Being overweight—the excess fat tissue around your neck 

makes it harder to keep the throat area open 

Head and neck shape that creates a somewhat smaller airway 

size in the mouth and throat area 

Congestion, due to allergies, that also can narrow the airway 

Family history of sleep apnea 

If your doctor suspects that you have sleep apnea, you may be 

referred to a sleep specialist. Some of the ways to help diagnose 

sleep apnea include: 

A medical history that includes asking you and your family 

questions about how you sleep and how you function during 

the day. 

Checking your mouth, nose, and throat for extra or large 

tissues—for example, checking the tonsils, uvula (the tissue 

that hangs from the middle of the back of the mouth), and soft 

palate (the roof of your mouth in the back of your throat). 

An overnight recording of what happens with your breathing 

during sleep (polysomnogram, or PSG). 

A multiple sleep latency test (MSLT), usually done in a sleep 

center, to see how quickly you fall asleep at times when you 

would normally be awake. (Falling asleep in only a few 

minutes usually means that you are very sleepy during the day. 

Being very sleepy during the day can be a sign of sleep apnea.) 

Common Sleep Disorders 
42 Your Guide to Healthy Sleep 

n	 

n	 

n	 

 

 

 

 

 

 

 

 

Once all the tests are completed, the sleep specialist will review the 

results and work with you and your family to develop a treatment 

plan. Changes in daily activities or habits may help reduce your 

symptoms: 

Sleep on your side instead of on your back. Sleeping on your 

side will help reduce the amount of upper airway collapse 

during sleep. 

Avoid alcohol, smoking, sleeping pills, herbal supplements, 

and any other medications that make you sleepy. They make 

it harder for your airways to stay open while you sleep, and 

sedatives can make the breathing pauses longer and more 

severe. Tobacco smoke irritates the airways and can help 

trigger the intermittent collapse of the upper airway. 

Lose weight if you are overweight. Even a little weight loss 

can sometimes improve symptoms. 

These changes may be all that are needed to treat mild sleep apnea. 

However, if you have moderate or severe sleep apnea, you will need 

additional, more direct treatment approaches. 

Continuous positive airway pressure (CPAP) is the most effective 

treatment for sleep apnea in adults. A CPAP machine uses mild air 

pressure to keep your airways open while you sleep. The machine 

delivers air to your airways through a specially designed nasal mask. 

The mask does not breathe for you; the flow of air creates increased 

pressure to keep the airways in your nose and mouth more open 

while you sleep. The air pressure is adjusted so that it is just enough 

to stop your airways from briefly becoming too small during sleep. 

The pressure is constant and continuous. Sleep apnea will return if 

CPAP is stopped or if it is used incorrectly. 

People who have severe sleep apnea symptoms generally feel much 

better once they begin treatment with CPAP. CPAP treatment can 

cause side effects in some people. Possible side effects include dry or 

stuffy nose, irritation of the skin on the face, bloating of the stomach, sore eyes, or headaches. If you have trouble with CPAP side 

effects, work with your sleep specialist and support staff. Together, 

you can do things to reduce or eliminate these problems. 

Currently, no medications cure sleep apnea. However, some 

prescription medications may help relieve the excessive sleepiness 

that sometimes persists even with CPAP treatment of sleep apnea. 
43 

My doctor prescribed CPAP (continuous positive airway 

pressure) for me, but it was not easy to use at first. Sleeping 

with a CPAP machine was uncomfortable for me, so I didn’t use 

it like I should have—rarely, if at all. One day at work, I started 

feeling really bad, so I went to the hospital. The doctors told 

me that since I had not been using CPAP regularly, not enough 

oxygen was going to my brain, which caused symptoms like 

those for a stroke. So, I went back to my doctor and got a 

different CPAP machine that was more comfortable for me. 

“It’s important to talk with your health care provider to make 

sure that your treatment is comfortable and works for you.

JIM 

“ 

” 

Another treatment approach that may help some people is the use of 

a mouthpiece (oral or dental appliance). If you have mild sleep 

apnea or do not have sleep apnea but snore very loudly, your doctor 

or dentist also may recommend this. A custom-fitted plastic mouthpiece will be made by a dentist or an orthodontist (a specialist in 

correcting teeth or jaw problems). The mouthpiece will adjust your 

lower jaw and tongue to help keep the airway in your throat more 

open while you are sleeping. Air can then flow more easily into your 

lungs because there is less resistance to breathing. Following up 

with the dentist or orthodontist is important to correct any side 

effects and to be sure that your mouthpiece continues to fit properly. 

It is also important to have a followup sleep study to see whether 

your sleep apnea has improved. 

Some people who have sleep apnea may benefit from surgery; this 

depends on the findings of the evaluation by the sleep specialist. 

Removing tonsils and adenoids that are blocking the airway is done 

frequently, especially in children. Uvulopalatopharyngoplasty 

(UPPP) is a surgery for adults that removes the tonsils, uvula, and 

part of the soft palate. Tracheostomy is a surgery used rarely and 

only in severe sleep apnea when no other treatments have been 

successful. A small hole is made in the windpipe, and a tube is 

inserted. Air will flow through the tube and into the lungs, bypassing the obstruction in the upper airway. 

Common Sleep Disorders 
44 Your Guide to Healthy Sleep 

 

l	 

l	 

l	 

How Are

 Sleep disorders diagnosed?

Depending on your symptoms, your doctor will gather information and consider several possible tests when trying to diagnose a 

sleep disorder: 

 

Sleep history and sleep log. Your doctor will ask you how 

many hours you sleep each night, how often you awaken during 

the night and for how long, how long it takes you to fall asleep, 

how well rested you feel upon awakening, and how sleepy you 

feel during the day. Your doctor may ask you to keep a sleep 

diary for a few weeks. (See “Sample Sleep Diary” on page 54.) 

Your doctor also may ask you whether you have any symptoms 

of sleep apnea or restless legs syndrome, such as loud snoring, 

snorting or gasping, morning headaches, tingling or unpleasant 

sensations in the limbs that are relieved by moving them, and 

jerking of the limbs during sleep. Your sleeping partner may be 

asked whether you have some of these symptoms, as you may 

not be aware of them yourself. 

Sleep recording in a sleep laboratory (polysomnogram). 

A sleep recording or polysomnogram (PSG) is usually done 

while you stay overnight at a sleep center or sleep laboratory. 

Electrodes and other monitors are placed on your scalp, 

face, chest, limbs, and finger. While you sleep, these devices 

measure your brain activity, eye movements, muscle activity, 

heart rate and rhythm, blood pressure, and how much air 

moves in and out of your lungs. This test also checks the 

amount of oxygen in your blood. A PSG test is painless. In 

certain circumstances, the PSG can be done at home. A home 

monitor can be used to record heart rate, how air moves in and 

out of your lungs, the amount of oxygen in your blood, and your 

breathing effort. 

Multiple sleep latency test (MSLT). This daytime sleep study 

measures how sleepy you are and is particularly useful for 

diagnosing narcolepsy. The MSLT is conducted in a sleep 
45 

laboratory and typically done after an overnight sleep recording 

(PSG). In this test, monitoring devices for sleep stage are 

placed on your scalp and face. You are asked to nap four 

or five times for 20 minutes every 2 hours during the day. 

Technicians note how quickly you fall asleep and how long it 

takes you to reach various stages of sleep, especially REM 

sleep, during your naps. Normal individuals either do not fall 

asleep during these short designated naptimes or take a long 

time to fall asleep. People who fall asleep in less than 

5 minutes are likely to require treatment for a sleep disorder, 

as are those who quickly reach REM sleep during their naps. 

It is important to have a sleep specialist interpret the results of 

your PSG or MSLT. See “How To Find a Sleep Center and Sleep 

Specialist” on page 56. 

Common Sleep Disorders 
46 Your Guide to Healthy Sleep 

I started to get weird feelings in my legs at 

night while I slept. To feel better, I would 

get up and move around and stretch. Then 

the weird feelings began to happen more 

often and made me lose sleep. I started to 

think that something was wrong. I decided 

to go to the doctor and was diagnosed with 

restless legs syndrome (RLS).

“Because RLS symptoms can 

change, I’m always trying to find 

the right mix of diet, medication, 

and exercise. Exercise and 

massage help me manage my 

RLS. Yoga helps a lot too, 

because of all the stretching 

involved.

LAUREN 

“ 

” 
47 

 

 

 

 

 

 

Restless Legs Syndrome 

Restless legs syndrome (RLS) causes an unpleasant prickling or 

tingling in the legs, especially in the calves, that is relieved by moving or massaging them. People who have RLS feel a need to stretch 

or move their legs to get rid of the uncomfortable or painful feelings. 

As a result, it may be difficult to fall asleep and stay asleep. One or 

both legs may be affected. Some people also feel the sensations in 

their arms. These sensations also can occur when lying down or 

sitting for long periods of time, such as while at a desk, riding in a 

car, or watching a movie. 

Many people who have RLS also have brief limb movements during 

sleep, often with abrupt onset, occurring every 5–90 seconds. This 

condition, known as periodic limb movements in sleep (PLMS), can 

repeatedly awaken people who have RLS, reducing their total sleep 

time and interrupting their sleep. Some people have PLMS but have 

no abnormal sensations in their legs while awake. 

RLS affects 5–15 percent of Americans, and its prevalence increases 

with age. RLS occurs more often in women than men. One study 

found that RLS accounted for one-third of the insomnia seen in 

patients older than age 60. Children also can have RLS. In children, 

the condition may be associated with symptoms of attention-deficit 

hyperactivity disorder. However, it’s not fully known how the 

disorders are related. Sometimes “growing pains” can be mistaken 

for RLS. 

RLS is often inherited. Pregnancy, kidney failure, and anemia 

related to iron or vitamin deficiency can trigger or worsen RLS 

symptoms. Researchers suspect that these conditions cause an iron 

deficiency that results in a lack of dopamine, which is used by the 

brain to control physical sensation and limb movements. Doctors 

usually can diagnose RLS by patients’ symptoms and a telltale 

worsening of symptoms at night or while at rest. Some doctors may 

order a blood test to check ferretin levels (ferretin is a form of iron). 

Doctors also may ask people who have RLS to spend a night in a 

sleep laboratory, where they are monitored to rule out other sleep 

disorders and to document the excessive limb movements. 

RLS is treatable but not always curable. Dramatic improvements 

are seen quickly when patients are given dopamine-like drugs or 

iron supplements. Alternatively, people who have milder cases may 

be treated successfully with sedatives or behavioral strategies. These 

Common Sleep Disorders 
48 Your Guide to Healthy Sleep 

 

 

 

 

 

 

 

 

n	 

strategies include stretching, taking a hot bath, or massaging the legs 

before bedtime. Avoiding caffeinated beverages also can help reduce 

symptoms, and certain medications (e.g., some antidepressants, 

particularly selective serotonin reuptake inhibitors) may cause RLS. 

If iron or vitamin deficiency underlies RLS, symptoms may improve 

with prescribed iron, vitamin B12, or folate supplements. Some 

people may require anticonvulsant medications to control the 

creeping and crawling sensations in their limbs. Others who have 

severe symptoms that are associated with another medical disorder 

or that do not respond to normal treatments may need to be treated 

with pain relievers. 

Narcolepsy 

Narcolepsy’s main symptom is extreme and overwhelming daytime 

sleepiness, even after adequate nighttime sleep. In addition, 

nighttime sleep may be fragmented by frequent awakenings. People 

who have narcolepsy often fall asleep at inappropriate times and 

places. Although TV sitcoms occasionally feature these individuals 

to generate a few laughs, narcolepsy is no laughing matter. People 

who have narcolepsy experience daytime “sleep attacks” that last 

from seconds to more than one-half hour, can occur without 

warning, and may cause injury. These embarrassing sleep spells also 

can make it difficult to work and to maintain normal personal or 

social relationships. 

With narcolepsy, the usually sharp distinctions between being asleep 

and awake are blurred. Also, people who have narcolepsy tend to 

fall directly into dream-filled REM sleep, rather than enter REM 

sleep gradually after passing through the non-REM sleep stages first. 

In addition to overwhelming daytime sleepiness, narcolepsy has 

three other commonly associated symptoms, but these may not 

occur in all people: 

Sudden muscle weakness (cataplexy). This weakness is similar 

to the paralysis that normally occurs during REM sleep, but it 

lasts a few seconds to minutes while an individual is awake. 

Cataplexy tends to be triggered by sudden emotional reactions, such as anger, surprise, fear, or laughter. The weakness 

may show up as limpness at the neck, buckling of the knees, 

or sagging facial muscles affecting speech, or it may cause a 

complete body collapse. 
49 Common Sleep Disorders 

At first, I was misdiagnosed with chronic 

fatigue syndrome, because I was in my 

forties and narcolepsy symptoms usually 

start during the teen years. Because 

I didn’t have any of the symptoms of 

chronic fatigue syndrome other than 

sleepiness, I went to a neurologist for 

help. He noticed the cataplexy (muscle 

weakness) right away, and then I 

was officially diagnosed with 

narcolepsy and then later 

on with borderline sleep 

apnea.

“Even though there is no 

cure for narcolepsy, you 

can feel like you have control if 

you manage it well. 

“When you have narcolepsy, you live 

your life differently. But with a good 

plan and supportive friends and family, 

it all turns out OK.

SZE-PING

“ 

” 
50 Your Guide to Healthy Sleep 

n	 

n	 

 

 

 

 

 

 

Sleep paralysis. People who have narcolepsy may experience 

a temporary inability to talk or move when falling asleep or 

waking up, as if they were glued to their beds. 

Vivid dreams. These dreams can occur when people who 

have narcolepsy first fall asleep or wake up. The dreams are 

so lifelike that they can be confused with reality. 

Experts estimate that as many as 350,000 Americans have narcolepsy, but fewer than 50,000 are diagnosed. The disorder may be as 

widespread as Parkinson’s disease or multiple sclerosis, and more 

prevalent than cystic fibrosis, but it is less well known. Narcolepsy 

is often mistaken for depression, epilepsy, or the side 

effects of medicines. 

Narcolepsy can be difficult to diagnose in people 

who have only the symptom of excessive daytime 

sleepiness. It is usually diagnosed during an 

overnight sleep recording (PSG) that is followed 

by an MSLT. (See “How Are Sleep Disorders 

Diagnosed?” on page 44.) Both tests reveal 

symptoms of narcolepsy—the tendency to 

fall asleep rapidly and enter REM sleep 

early, even during brief naps. 

Narcolepsy can develop at any age, but 

the symptoms tend to appear first during 

adolescence or early adulthood. About 1 

of every 10 people who have narcolepsy 

has a close family member who has the 

disorder, suggesting that one can inherit 

a tendency to develop narcolepsy. 

Studies suggest that a substance in the 

brain called hypocretin plays a key 

role in narcolepsy. Most people who 

have narcolepsy lack hypocretin, which 

promotes wakefulness. Scientists believe that 

an autoimmune reaction—perhaps triggered 

by disease, viral illness, or brain injury— 

specifically destroys the hypocretin-generating 

cells in the brains of people who have 

narcolepsy. 
51 

 

 

 

 

 

Eventually, researchers may develop a treatment for narcolepsy that 

restores hypocretin to normal levels. In the meantime, most people 

who have narcolepsy find some to all of their symptoms relieved by 

various drug treatments. For example, central nervous system 

stimulants can reduce daytime sleepiness. Antidepressants and other 

drugs that suppress REM sleep can prevent muscle weakness, sleep 

paralysis, and vivid dreaming. Doctors also usually recommend that 

people who have narcolepsy take short naps (10–15 minutes) two or 

three times a day, if possible, to help control excessive daytime 

sleepiness. 

Parasomnias (Abnormal Arousals) 

In some people, the walking, talking, and other body functions 

normally suppressed during sleep occur during certain sleep stages. 

Alternatively, the paralysis or vivid images usually experienced 

during dreaming may persist after awakening. These occurrences 

are collectively known as parasomnias and include confusional 

arousals (a mixed state of being both asleep and awake), sleep 

talking, sleep walking, night terrors, sleep paralysis, and REM sleep 

behavior disorder (acting out dreams). Most of these disorders— 

such as confusional arousals, sleep walking, and night terrors—are 

more common in children, who tend to outgrow them once they 

become adults. People who are sleep-deprived also may experience 

some of these disorders, including sleep walking and sleep paralysis. 

Sleep paralysis also commonly occurs in people who have narcolepsy. Certain medications or neurological disorders appear to lead 

to other parasomnias, such as REM sleep behavior disorder, and 

these parasomnias tend to occur more in elderly people. If you or a 

family member has persistent episodes of sleep paralysis, sleep 

walking, or acting out of dreams, talk with your doctor. Taking 

measures to assure the safety of children and other family members 

who have partial arousals from sleep is very important. 

Common Sleep Disorders 
52 Your Guide to Healthy Sleep 

It’s a scary experience, lying in bed, wanting 

to get up, but unable to—scary enough to 

almost make you not want to go to sleep 

anymore. I can remember, as a child, feeling 

as though there was a weight on me when 

I was trying to wake up, and I couldn’t 

move. When I would try to wake up, I would 

kick my legs and flail my arms, sometimes 

bumping my wife. I really didn’t have control 

over my limbs. 

“When the symptoms got really bad, I went 

to a sleep specialist, who told me I had sleep 

paralysis. My doctor prescribed a medicine 

that has worked great for me. Now, I rarely 

have sleep paralysis—maybe 3 times per 

year.

LAWRENCE

“ 

” 
53 

 

 

 

n

n

n

n

Do You Think You Have a 

Sleep Disorder? 

At various points in our lives, all of us suffer from a lack of sleep 

that can be corrected by making sure we have the opportunity to get 

enough sleep. But, if you are spending enough time in bed and still 

wake up tired or feel very sleepy during the day, you may have a 

sleep disorder. See “Common Signs of a Sleep Disorder” on page 34. 

One of the best ways you can tell whether you are getting enough 

good-quality sleep, and whether you have signs of a sleep disorder, is 

by keeping a sleep diary. (See “Sample Sleep Diary” on page 54.) 

Use this diary to record the quality and quantity of your sleep; your 

use of medications, alcohol, and caffeinated beverages; your exercise 

patterns; and how sleepy you feel during the day. After a week or 

so, look over this information to see how many hours of sleep or 

nighttime awakenings one night are linked to your being tired the 

next day. This information will give you a sense of how much 

uninterrupted sleep you need to avoid daytime sleepiness. You also 

can use the diary to see some of the patterns or practices that may 

keep you from getting a good night’s sleep. 

You may have a sleep disorder and should see your doctor if your 

sleep diary reveals any of the following: 

You consistently take more than 30 minutes each night to fall 

asleep. 

You consistently awaken more than a few times or for long 

periods of time each night. 

You take frequent naps. 

You often feel sleepy during the day—or you fall asleep at 

inappropriate times during the day. 

Do You Think You Have a Sleep Disorder? 
54 

Sample Sleep Diary
 

Name:

Complete in the Morning 

Today’s date (include 

month/day/year): 

Monday* 

Time I went to bed last night: 

Time I woke up this morning: 

No. of hours slept last night: 

11 p.m. 

7 a.m. 

8 

Number of awakenings and 

total time awake last night: 

5 times 

2 hours 

How long I took to fall asleep 

last night: 

30 mins. 

Medications taken last night: None 

How awake did I feel when 

I got up this morning? 

1—Wide awake 

2—Awake but a little tired 

3—Sleepy 

2 

Complete in the Evening 

Number of caffeinated drinks 

(coffee, tea, cola) and time 

when I had them today: 

1 drink at 

8 p.m. 

Number of alcoholic drinks 

(beer, wine, liquor) and time 

when I had them today: 

2 drinks 

9 p.m. 

Naptimes and lengths today: 3:30 p.m. 

45 mins. 

Exercise times and lengths 

today: 

None 

How sleepy did I feel during 

the day today? 

1—So sleepy had to struggle 

1 

to stay awake during much of 

the day 

2—Somewhat tired 

3—Fairly alert 

4—Wide awake 

Your Guide to Healthy Sleep

* This column shows example diary entries—use as a model for your own diary notes. 
55 Do You Think You Have a Sleep Disorder? 
56 Your Guide to Healthy Sleep 

How To Find a Sleep Center 

and Sleep Specialist 

If your doctor refers you to a sleep center or sleep specialist, make 

sure that center or specialist is qualified to diagnose and treat your 

sleep problem. To find sleep centers accredited by the American 

Academy of Sleep Medicine, go to 

www.aasmnet.org and click on “Find a 

Sleep Center” (under the Patients & Public 

menu), or call 708–492–0930. To find 

sleep specialists certified by the American 

Board of Sleep Medicine, go to 

www.absm.org and click on 

“Verification of Diplomates of 

the ABSM.” 
57 

 

 

 

n

n

n

n

Research
 

Researchers have learned a lot about sleep and sleep disorders in 

recent years. That knowledge has led to a better understanding of 

the importance of sleep to our lives and our health. Research 

supported by the National Heart, Lung, and Blood Institute 

(NHLBI) has helped identify some of the causes of sleep disorders 

and their effects on the heart, brain, lungs, and other body systems. 

The NHLBI also supports ongoing research on the most effective 

ways to diagnose and treat sleep disorders. 

Many questions remain about sleep and sleep disorders. The 

NHLBI continues to support a range of research that focuses on: 

Better understanding of how a lack of sleep increases the risk

for obesity, diabetes, heart disease, and stroke 

New ways to diagnose sleep disorders 

Genetic, environmental, and social factors that lead to sleep 

disorders 

The adverse effects from a lack of sleep on body and brain 

Much of this research depends on the willingness of volunteers to 

participate in clinical research. If you would like to help researchers 

advance science on sleep or about a sleep disorder you have and 

possible treatments, talk to your doctor about participating in 

clinical research. (For more information, see “Clinical Research” on 

page 58.) 

Research 
58 Your Guide to Healthy Sleep 

Clinical 

 research

Researchers can learn quite a bit about sleep and sleep disorders 

by studying animals. However, to fully understand sleep and 

its affect on health and functioning, as well as how best to 

diagnose and treat sleep disorders, researchers need to do 

clinical research on people. This type of research is called clinical 

research because it is often conducted in clinical settings, such 

as hospitals or doctors’ offices. 

The two types of clinical research are clinical trials and clinical 

studies. 

l	 Clinical trials test new ways to diagnose, prevent, or 

treat various disorders.  For example, treatments (such as 

medicines, medical devices, surgery, or other procedures) 

for a disorder need to be tested in people who have the 

disorder.  A trial helps determine whether a treatment is safe 

and effective in humans before it is made available for public 

use. In a clinical trial, participants are randomly assigned 

to groups.  One group receives the new treatment being 

tested.  Other groups may receive a different treatment or 

a placebo (an inactive substance resembling a drug being 

tested).  Comparing results from the groups gives researchers 

confidence that changes in the test group are due to the new 

treatment and not to other factors. 
59 

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Other types of clinical studies are done to discover the 

factors, including environmental, behavioral, or genetic 

factors, that cause or worsen various disorders. Researchers 

may follow a group of people over time to learn what factors 

contribute to becoming sick. 

Clinical studies and trials may be relatively brief, or may last for 

years and require many visits to the study sites. These sites 

usually are university hospitals or research centers, but they can 

include private doctors’ offices and community hospitals. 

If you participate in clinical research, the research will be 

explained to you in detail, you will be given a chance to ask 

questions, and you will be asked to provide written permission. 

You may not directly benefit from the results of the clinical 

research you participate in, but the information gathered will 

help others and will add to scientific knowledge. Taking part in 

clinical research has other benefits, as well. You’ll learn more 

about your disorder, you’ll have the support of a team of health 

care providers, and your health will likely be monitored closely. 

However, participation also can have risks, which you should 

discuss with your doctor. No matter what you decide, your 

regular medical care will not be affected. 

If you’re thinking about participating in a clinical study, you may 

have questions about the purpose of the study, the types of tests 

and treatment involved, how participation will affect your daily life, 

and whether any costs are involved. Your doctor may be able to 

answer some of your questions and help you find clinical studies 

in which you can participate. You also can visit the following Web 

sites to learn about being in a study and to search for clinical 

trials being done on your disorder: 

www.clinicaltrials.gov 

http://clinicalresearch.nih.gov 

www.nhlbi.nih.gov/studies/index.htm 

Clinical Research
 

Research 
60 Your Guide to Healthy Sleep 

 

For More Sleep Information
 

Resources From the National Heart, Lung, and Blood Institute (NHLBI) 

National Center on Sleep Disorders Research 

Division of Lung Diseases, NHLBI 

Two Rockledge Centre, Suite 10170 

6701 Rockledge Drive 

Bethesda, MD 20895–7952 

Phone: 301–435–0199 

Fax: 301–480–3451 

Web site: www.nhlbi.nih.gov/sleep 

NHLBI Diseases and Conditions Index (DCI) 

The DCI includes articles on sleep disorders, tests,
 

and procedures, along with videos, podcasts, and 


Spanish-language articles.
 

Web site: www.nhlbi.nih.gov/health/dci/index.html
 

NHLBI Health Information Center 

P.O. Box 30105 

Bethesda, MD 20824–0105 

Telephone: 301–592–8573 

TTY: 240–629–3255 

Fax: 301–592–8563 

E-mail: nhlbiinfo@nhlbi.nih.gov 

Web site: www.nhlbi.nih.gov 

NIH Office of Science Education Web site (for high school 

supplemental curriculum: Sleep, Sleep Disorders, and 

Biological Rhythms) 

http://science.education.nih.gov 
61 

 

 

 

 

Resources From Other Sleep Organizations 

American Academy of Sleep Medicine (AASM) 

2510 North Frontage Road 

Darien, IL 60561 

Telephone: 630–737–9700 

Fax: 630–737–9790 

Web site: www.aasmnet.org 

American Sleep Apnea Association 

6856 Eastern Avenue, NW., Suite 203 

Washington, DC 20012 

Telephone: 202–203–3650 

Fax: 202–293–3656 

Web site: www.sleepapnea.org 

Narcolepsy Network 

P.O. Box 294 

Pleasantville, NY 10570 

Telephone: 401–667–2523 

Fax: 401–633–6567 

E-mail: narnet@narcolepsynetwork.org 

Web site: www.narcolepsynetwork.org 

National Sleep Foundation 

1010 North Glebe Road, Suite 310 

Arlington, VA 22201 

Telephone: 703–243–1697 

E-mail: nsf@sleepfoundation.org 

Web site: www.sleepfoundation.org 

Restless Legs Syndrome Foundation 

1610 14th Street, NW., Suite 300 

Rochester, MN 55901 

Telephone: 507–287–6465 

Fax: 507–287–6312 

E-mail: rlsfoundation@rls.org 

Web site: www.rls.org 

For More Sleep Information 
62 Your Guide to Healthy Sleep 

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Notes
 

Notes 

Discrimination Prohibited: Under provisions of 

applicable public laws enacted by Congress 

since 1964, no person in the United States shall, 

on the grounds of race, color, national origin, 

handicap, or age, be excluded from participation 

in, be denied the benefits of, or be subjected to 

discrimination under any program or activity (or, 

on the basis of sex, with respect to any education program or activity) receiving Federal financial assistance. In addition, Executive Order 

11141 prohibits discrimination on the basis of 

age by contractors and subcontractors in the 

performance of Federal contracts, and Executive 

Order 11246 states that no federally funded contractor may discriminate against any employee or 

applicant for employment because of race, color, 

religion, sex, or national origin. Therefore, the 

National Heart, Lung, and Blood Institute must be 

operated in compliance with these laws and 

Executive Orders.
NIH Publication No. 11-5271

Originally printed November 2005

Revised August 2011