Sleepwalking

# Overview
Sleepwalking (also called somnambulism or noctambulism), under the larger category of parasomnias or sleep disorders where the sufferer engages in activities that are normally associated with wakefulness while he or she is asleep or in a sleeplike state. Sleepwalking is usually defined by, or involves the person affected apparently shifting from his or her prior sleeping position and moving around and performing normal actions as if awake (cleaning, walking and other activities). Sleepwalkers are not conscious of their actions on a level where memory of the sleepwalking episode can be recalled, and because of this, unless the sleepwalker is woken or aroused by someone else, this sleep disorder can go unnoticed. Sleepwalking is more commonly experienced in people with high levels of stress, anxiety or other psychological factors and in people with genetic factors (family history) or sometimes a combination of both.
A common misconception is that sleepwalking is an individual acting out the physical movements within a dream, but in fact sleepwalking occurs earlier on in the night when rapid eye movement (REM), or the "dream stage" of sleep, has not yet occurred.

# Explanation
A majority of people move their legs while sleeping; however, sleepwalking occurs when both legs move in synchronization, which is much less common.
Sleepwalking can affect people of any age. It generally occurs when an individual awakes suddenly from slow wave sleep (SWS, sometimes referred to as "deep sleep"); causing the sleepwalking episode. In children and young adults, up to 25% of the night is spent in SWS. However this decreases as the person ages until none can be measured in the geriatric individual. For this reason, children and young adults (or anyone else with a high amount of SWS), are more likely to be woken up and, for the same reasons, they are witnessed to have many more episodes than the older individuals.

# Statistics
- 85% of the world's population is prone to sleepwalking.
- Somewhere between 1% and 16.7% of U.S. children sleepwalk, and juveniles are seen to be those more prone to the activity.
- One study showed that the highest prevalence of sleepwalking was 16.7% for children of 11 to 12 years of age.
- Males are seen to be more likely to sleepwalk than females.
Activities such as eating, bathing, urinating, dressing, or even driving cars, whistling, engaging in sexual intercourse, and committing murder have also been recorded as taking place while the subjects are technically asleep. Contrary to popular belief, most cases of sleepwalking do not consist of walking around (without the conscious knowledge of the subject). Most cases of somnambulism occur when the person is awakened (something or someone disturbs their SWS), the person may sit up, look around and immediately go back to sleep. But these kinds of incidences are rarely noticed or reported unless recorded in a sleep clinic.
Sleepwalkers engage in their activities with their eyes open so they can navigate their surroundings, not with their eyes closed and their arms outstretched, as often parodied in cartoons and films. The victims' eyes may have a glazed or empty appearance and if questioned, the subject will be slow to answer and will be unable to respond in an intelligible manner.

# Hazards
Sleepwalkers are more likely to endanger themselves than anyone else. When sleepwalkers are a danger to themselves or others (for example, when climbing up or down steps or trying to use a potentially dangerous tool such as a stove or a knife), steering them away from the danger and back to bed is advisable. It has even been reported that people have fallen out of windows, and died, or were injured as a result. However, sleepwalkers will only engage in behaviors they normally perform when awake. Sleepwalking should not be confused with psychosis.
In some rare cases, sleepwalkers have committed a homicidal act during sleepwalking.

# Causes

## Causes by Organ System

## Causes in Alphabetical Order

# Dealing with sleepwalkers
Often the best way to deal with a sleepwalker safely is to direct him or her back to the bed. However, the person may continue getting up until he or she has accomplished the task that prompted the sleepwalking in the first place. For instance, if a sleepwalker is cleaning - a common sleepwalking activity - assisting in the cleaning may help to end the episode. Telling the person "It looks like you have cleaned it all up" can help him or her to feel as though the "necessary" task has been accomplished. As sleepwalkers do not tend to remember anything said or done while sleepwalking, there is no need to worry about embarrassment to you or the individual afterward.
Sleepwalkers are highly suggestible. Anything they hear or see may trigger another behavior. Often something said by a person or even on a television will cause the sleepwalker to engage in the activity mentioned, provided it is one to which he or she is accustomed to hearing about or doing. If the sleepwalker is also talking, it may be helpful to ask what he or she is trying to accomplish. Ask very simple questions that can be answered in short, simple replies. If asked a question that requires a long answer or explanation, the sleepwalker is unlikely to respond coherently. Talking during sleepwalking varies from person to person and may not always be useful in dealing with a sleepwalker. Because sleepwalkers are unaware of their present surroundings, they may divulge information that they would otherwise keep secret. They may also exhibit behaviors which would be considered embarrassing, such as urinating in inappropriate places, trying to eat invisible foods, cleaning invisible counters, or even trying to bathe or engage in sexual intercourse.

# Trivia
- The 19th Century German chemist and metaphysician Baron Karl Ludwig von Reichenbach made extensive studies of sleepwalkers, and used his discoveries to formulate his theory of the Odic force.
- Sleepwalking is a major theme in the classic silent German Expressionist film Das Kabinett des Dr. Kaligari (English title: The Cabinet of Dr. Caligari) 1920.
- In Shakespeare's famous  play Macbeth, Lady Macbeth is mentioned to be a sleepwalker, leading up to her eventual madness and suicide.
- In Dario Argento's Phenomena (1985), the protagonist, Jennifer Corvino (Jennifer Connelly) is a sleepwalker, and witnesses one of the film's murders in her sleepwalking state.
- In the film adaption of Silent Hill, the protagonist's daughter suffers from sleepwalking, and is apparently medicated to prevent the condition.