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Sleep paralysis introduction

Have you ever felt like you were awake but unable to move? You might have even felt afraid but could not call for help? This condition is called sleep paralysis. Sleep paralysis may leave you feeling frightened, especially if you also see or hear things that aren't really there. Sleep paralysis may happen only once, or you may have it frequently -- even several times a night.

The good news: sleep paralysis is not considered a dangerous health problem. Read on to find out more about sleep paralysis, its possible causes, and its treatment.

Is sleep paralysis a symptom of a serious problem?

Sleep researchers conclude that, in most cases, sleep paralysis is simply a sign that your body is not moving smoothly through the stages of sleep. Rarely is sleep paralysis linked to deep underlying psychiatric problems.

Over the centuries, symptoms of sleep paralysis have been described in many ways and often attributed to an "evil" presence: unseen night demons in ancient times, the old hag in Shakespeare's Romeo and Juliet, and alien abductors. Almost every culture throughout history has had stories of shadowy evil creatures that terrify helpless humans at night. People have long sought explanations for this mysterious sleep-time paralysis and the accompanying feelings of terror.

What is sleep paralysis?

Sleep paralysis is a feeling of being conscious but unable to move. It occurs when a person passes between stages of wakefulness and sleep. During these transitions, you may be unable to move or speak for a few seconds up to a few minutes. Some people may also feel pressure or a sense of choking. Sleep paralysis may accompany other sleep disorders such as narcolepsy. Narcolepsy is an overpowering need to sleep caused by a problem with the brain's ability to regulate sleep.

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Sleep Paralysis Definition

A frightening form of paralysis that occurs when a person suddenly finds himself or herself unable to move for a few minutes, most often upon falling asleep or waking up. Sleep paralysis is due to an irregularity in passing between the stages of sleep and wakefulness.

The symptoms of sleep paralysis include sensations of noises, smells, levitation, paralysis, terror, and images of frightening intruders. Once considered very rare, up to half of all people are now believed to experience sleep paralysis sometime during their life. Sleep paralysis is not considered to be a sign of a serious condition, although it can be frightening.

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When does sleep paralysis usually occur?

Sleep paralysis usually occurs at one of two times. If it occurs while you are falling asleep, it's called hypnagogic or predormital sleep paralysis. If it happens as you are waking up, it's called hypnopompic or postdormital sleep paralysis.

What happens with hypnagogic sleep paralysis?

As you fall asleep, your body slowly relaxes. Usually you become less aware, so you do not notice the change. However, if you remain or become aware while falling asleep, you may notice that you cannot move or speak.

What happens with hypnopompic sleep paralysis?

During sleep, your body alternates between REM (rapid eye movement) and NREM (non-rapid eye movement) sleep. One cycle of REM and NREM sleep lasts about 90 minutes. NREM sleep occurs first and takes up to 75% of your overall sleep time. During NREM sleep, your body relaxes and restores itself. At the end of NREM, your sleep shifts to REM. Your eyes move quickly and dreams occur, but the rest of your body remains very relaxed. Your muscles are "turned off" during REM sleep. If you become aware before the REM cycle has finished, you may notice that you cannot move or speak.

Who develops sleep paralysis?

Up to as many as four out of every 10 people may have sleep paralysis. This common condition is often first noticed in the teen years. But men and women of any age can have it. Sleep paralysis may run in families. Other factors that may be linked to sleep paralysis include:

How is sleep paralysis diagnosed?

If you find yourself unable to move or speak for a few seconds or minutes when falling asleep or waking up, then it is likely you have isolated recurrent sleep paralysis. Often there is no need to treat this condition. However, check with your doctor if you have any of these concerns:

  • you feel anxious about your symptoms
  • your symptoms leave you very tired during the day
  • your symptoms keep you up during the night

Your doctor may want to gather more information about your sleep health by doing any of these things:

  • ask you to describe your symptoms and keep a sleep diary for a few weeks
  • discuss your health history, including any known sleep disorders or any family history of sleep disorders
  • refer you to a sleep specialist for further evaluation
  • conduct overnight sleep studies or daytime nap studies to make sure you do not have another sleep disorder

How is sleep paralysis treated?

Most people need no treatment for sleep paralysis. Treating any underlying conditions such as narcolepsy may help if you are anxious or unable to sleep well. These treatments may include the following:

  • improving sleep habits -- such as making sure you get six to eight hours of sleep each night
  • using antidepressant medication to help regulate sleep cycles
  • treating any mental health problems that may contribute to sleep paralysis
  • treating any other sleep disorders, such as narcolepsy or leg cramps

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What can I do about sleep paralysis?

There's no need to fear nighttime demons or alien abductors. If you have occasional sleep paralysis, you can take steps at home to control this disorder. Start by making sure you get enough sleep. Do what you can to relieve stress in your life -- especially just before bedtime. Try new sleeping positions if you sleep on your back. And be sure to see your doctor if sleep paralysis routinely prevents you from getting a good night's sleep.

WebMD Medical Reference

SOURCES:
American Academy of Sleep Medicine: "Sleep Paralysis."
National Sleep Foundation: "Ask the Sleep Expert: Sleep & Parasomnias."
National Sleep Foundation: "Sleep Paralysis."
National Sleep Foundation: "Topics A to ZZZZs: Narcolepsy."
National Sleep Foundation: "What Happens When You Sleep?"

Reviewed by Louis R. Chanin, MD on March 03, 2010

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Reviewed on 3/19/2012 2:59:19 PM
References
WebMD Medical Reference

SOURCES:
American Academy of Sleep Medicine: "Sleep Paralysis."
National Sleep Foundation: "Ask the Sleep Expert: Sleep & Parasomnias."
National Sleep Foundation: "Sleep Paralysis."
National Sleep Foundation: "Topics A to ZZZZs: Narcolepsy."
National Sleep Foundation: "What Happens When You Sleep?"

Reviewed by Louis R. Chanin, MD on March 03, 2010

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