NIDCD Fact Sheet

Taste Disorders

u.s. department of health & human services ∙ national institutes of health ∙ National Institute on Deafness and Other Communication Disorders smell taste

How common are taste disorders?

Many of us take our sense of taste for granted, but a 

taste disorder can have a negative effect on a person’s 

health and quality of life. If you are having a problem 

with your sense of taste, you are not alone. More than 

200,000 people visit a doctor each year for problems 

with their chemical senses, which include taste and 

smell. 

The senses of taste and smell are very closely related. 

Some people who go to the doctor because they think 

they’ve lost their sense of taste are surprised to learn 

that they have a smell disorder instead. To learn more 

about your sense of smell, read the NIDCD fact sheet 

Smell Disorders at http://www.nidcd.nih.gov/health/

smelltaste/smell.asp. 

How does our sense of taste work?

Our ability to taste occurs when tiny molecules 

released by chewing, drinking, or digesting our 

food stimulates special sensory cells in the mouth 

and throat. These taste cells, or gustatory cells, are 

clustered within the taste buds of the tongue and roof 

of the mouth and along the lining of the throat. Many 

of the small bumps on the tip of our tongue contain 

taste buds. At birth, we have about 10,000 taste buds, 

but after age 50, we may start to lose them.

When the taste cells are stimulated, they send 

messages through three specialized taste nerves to the 

brain, where specific tastes are identified. Each taste 

cell expresses a receptor, which responds to one of at 

least five basic taste qualities: sweet, sour, bitter, salty, 

and umami. Umami, or savory, is the taste we get 

from glutamate, which is found in chicken broth, meat 

extracts, and some cheeses. A common misconception 

is that taste cells that respond to different tastes 

are found in separate regions of the tongue. In 

humans, the different types of taste cells are scattered 

throughout the tongue.

Taste quality is just one aspect of how we experience 

a certain food. Another chemosensory mechanism, 

called the common chemical sense, involves thousands 

of nerve endings, especially on the moist surfaces 

of the eyes, nose, mouth, and throat. These nerve 

endings give rise to sensations such as the coolness 

of mint and the burning or irritation of chili peppers. 

Other specialized nerves give rise to the sensations of 

heat, cold, and texture. When we eat, the sensations 

from the five taste qualities, together with the 

sensations from the common chemical sense and the 

sensations of heat, cold, and texture, combine with 

a food’s aroma to produce a perception of flavor. It is 

flavor that lets us know whether we are eating a pear 

or an apple. 

Many people who think they have a taste disorder 

actually have a problem with smell. When we chew, 

aromas are released that activate our sense of smell 

by way of a special channel that connects the roof 

of the throat to the nose. If this channel is blocked, 

such as when our noses are stuffed up by a cold or 

flu, odors cannot reach sensory cells in the nose that 

are stimulated by smells. As a result, much of our 

enjoyment of flavor is lost. Without smell, foods tend 

to taste bland and are flavorless. 
NIDCD Fact Sheet

Taste Disorders

What are the taste disorders?

The most common taste disorder is phantom taste 

perception—that is, a lingering, often unpleasant taste 

even though you have nothing in your mouth. We also 

can experience a reduced ability to taste sweet, sour, 

bitter, salty, and umami, a condition called hypogeusia. 

Some people cannot detect any tastes, which is called 

ageusia. True taste loss, however, is rare. Most often, 

people are experiencing a loss of smell as opposed to a 

loss of taste. 

In other disorders of the chemical senses, an odor, 

a taste, or a flavor may be distorted. Dysgeusia is a 

condition in which a foul, salty, rancid, or metallic 

taste sensation will persist in the mouth. Dysgeusia is 

sometimes accompanied by burning mouth syndrome, 

a condition in which a person experiences a painful 

burning sensation in the mouth. Although it can affect 

anyone, burning mouth syndrome is most common in 

middle-aged and older women.

What causes taste disorders?

Some people are born with taste disorders, but most 

develop them after an injury or illness. Among the 

causes of taste problems are:

• Upper respiratory and middle ear infections

• Radiation therapy for cancers of the head and neck 

• Exposure to certain chemicals, such as insecticides 

and some medications, including some common 

antibiotics and antihistamines

• Head injury

• Some surgeries to the ear, nose, and throat (e.g., 

third molar, or wisdom tooth, extraction and middle 

ear surgery)

• Poor oral hygiene and dental problems

How are taste disorders diagnosed?

Both taste and smell disorders are diagnosed by an 

otolaryngologist, a doctor of the ear, nose, throat, 

head, and neck. An otolaryngologist can determine 

the extent of your taste disorder by measuring the 

lowest concentration of a taste quality that you 

can detect or recognize. You also may be asked to 

compare the tastes of different substances or to note 

how the intensity of a taste grows when a substance’s 

concentration is increased.

Scientists have developed taste testing in which the 

patient responds to different chemical concentrations. 

This may involve a simple “sip, spit, and rinse” test, or 

chemicals may be applied directly to specific areas of 

the tongue.

An accurate assessment of your taste loss will include, 

among other things, a physical examination of your 

ears, nose, and throat; a dental examination and 

assessment of oral hygiene; a review of your health 

history; and a taste test supervised by a health care 

professional.

Are taste disorders serious?

Taste disorders can weaken or remove an early 

warning system that most of us take for granted. Taste 

helps us detect spoiled food or liquids and, for some 

people, the presence of ingredients to which they 

are allergic. 

Loss of taste can create serious health issues. A 

distorted sense of taste can be a risk factor for 

heart disease, diabetes, stroke, and other illnesses 

that require sticking to a specific diet. When taste 

is impaired, a person may change his or her eating 

habits. Some people may eat too little and lose weight, 

while others may eat too much and gain weight. 

smelltaste
• If your diet permits, add small amounts of cheese, 

bacon bits, butter, olive oil, or toasted nuts on 

vegetables.

• Avoid combination dishes, such as casseroles, that 

can hide individual flavors and dilute taste.

What research is being done?

The National Institute on Deafness and Other 

Communication Disorders (NIDCD) supports basic and 

clinical investigations of taste and smell disorders at 

institutions across the nation. Some of these studies 

are conducted at chemosensory research centers, 

where scientists work together to uncover how our 

gustatory system works.

Some of the most recent research in this area focuses 

on identifying the key receptors expressed by our 

taste cells and understanding how they work. So far, 

researchers have identified the taste cells and receptors 

for detecting sour, sweet, bitter, and umami tastes. 

Researchers are also working to develop a better 

understanding of how sweet and bitter substances 

attach to their targeted receptors. The goal is to 

develop noncaloric artificial sweeteners and bitter 

blockers, substances that block the bitter taste of some 

foods or medicines. 

A recent NIDCD-funded study has shown that small 

variations in our genetic code can raise or lower our 

sensitivity to sweet tastes, which might influence a 

person’s desire for sweets. Scientists have also made 

progress in understanding how our sense of taste 

changes as we age. Older adults often decide what 

to eat based on how much they like or dislike certain 

tastes. Scientists are looking at how and why this 

happens in order to develop more effective ways to 

help older people cope better with taste problems. 

more

Loss of taste can cause us to eat too much sugar 

or salt to make our food taste better. This can be a 

problem for people with certain medical conditions, 

such as diabetes or high blood pressure. In severe 

cases, loss of taste can lead to depression. 

Loss of taste and smell can also be a sign of certain 

degenerative diseases of the nervous system, such as 

Parkinson’s disease or Alzheimer’s disease. If you are 

experiencing a taste disorder, consult your physician. 

Can taste disorders be treated?

Many types of taste disorders are curable. For those 

that are not, counseling is available to help people 

adjust to their problem.

Diagnosis by an otolaryngologist is important to 

identify and treat the underlying cause of your 

disorder. If a certain medication is the cause, stopping 

or changing your medicine may help eliminate the 

problem. (Do not stop taking your medications unless 

directed by your doctor, however.) Some people, 

notably those with respiratory infections or allergies, 

regain their sense of taste when these conditions are 

resolved. Often, the correction of a general medical 

problem also can correct the loss of taste. Occasionally, 

a person may recover his or her sense of taste 

spontaneously. Proper oral hygiene is important to 

regaining and maintaining a well-functioning sense 

of taste.

If you lose some or all of your sense of taste, there are 

things you can do to make your food taste better:

• Prepare foods with a variety of colors and textures. 

• Use aromatic herbs and hot spices to add more 

flavor (however, avoid adding more sugar or salt 

to foods).
NIDCD supports and conducts research and research training on the 

normal and disordered processes of hearing, balance, smell, taste, 

voice, speech, and language and provides health information, based 

upon scientific discovery, to the public.

NIDCD Fact Sheet: Taste Disorders

Publication No. 09-3231A

Updated July 2009

For more information, contact:

NIDCD Information Clearinghouse

1 Communication Avenue

Bethesda, MD 20892-3456

Toll-free Voice: 800–241–1044

Toll-free TTY: 800–241–1055

E-mail: nidcdinfo@nidcd.nih.gov

Internet: http://www.nidcd.nih.gov

The NIDCD Information Clearinghouse is a service of the 

National Institute on Deafness and Other Communication 

Disorders, National Institutes of Health, U.S. Department 

of Health and Human Services.

hearing, balancevoice, speech, language

Scientists are also working to find out why some 

medications and medical procedures can have a 

harmful effect on our senses of taste and smell. They 

hope to develop treatments to help restore the sense 

of taste to people who have lost it. 

Scientists are gaining a better understanding of why 

the same receptor that helps our tongue detect sweet 

taste can also be found in the human gut. Recent 

research has shown that the sweet receptor helps 

the intestine to sense and absorb sugar and turn up 

the production of blood sugar-regulation hormones, 

including the hormone that regulates insulin release. 

Further research may help scientists develop drugs 

targeting the gut taste receptors to treat obesity 

and diabetes.

Finally, taste cells—as well as sensory cells that help us 

smell—are the only sensory cells in the human body 

that are regularly replaced throughout life. Researchers 

are exploring how and why this happens in order to 

find ways to replace other damaged sensory cells. 

NIDCD-supported research in the chemosensory 

sciences include studies to:

• Promote the regeneration of sensory and 

nerve cells. 

• Prevent the effects of aging. 

• Develop new diagnostic tests. 

• Understand associations among chemosensory 

disorders, altered food intake and diet, and 

major health risk factors (e.g., obesity and 

cardiovascular disease). 

• Improve treatment methods and 

rehabilitation strategies. 

smell, taste 

Where can I find more information?

The NIDCD maintains a directory of organizations that 

can answer questions and provide printed or electronic 

information about hearing, balance, smell, taste, voice, 

speech, and language. This directory is available at 

http://www.nidcd.nih.gov/directory.

To find organizations with information specifically 

about taste disorders, click on “Smell and Taste” in the 

“Browse by Topic” list. 

For more information, additional addresses and phone 

numbers, or a printed list of organizations, contact:

NIDCD Information Clearinghouse

1 Communication Avenue

Bethesda, MD 20892-3456

Toll-free Voice: (800) 241-1044

Toll-free TTY: (800) 241-1055

Fax: (301) 770-8977

E-mail: nidcdinfo@nidcd.nih.gov