Sleep paralysis is a temporary inability to move or speak that occurs when you're waking up or falling asleep.
It's not harmful and should pass in a few seconds or minutes, but can be very frightening.
Many people have sleep paralysis once or twice in their life, while others experience it a few times a month or more regularly.
It affects people of all ages and is most common in teenagers and young adults.
This page covers:
Symptoms of sleep paralysis
The main symptom of sleep paralysis is being completely aware of your surroundings but temporarily being unable to move or talk.
This usually occurs as you're waking up, but can happen when falling asleep.
During an episode of sleep paralysis you may:
- find it difficult to take deep breaths, as if your chest is being crushed or restricted
- be able to move your eyes - some people can also open their eyes but others find they can't
- have a sensation that there's someone or something in the room with you (hallucination) - many people feel this presence wishes to harm them
- feel very frightened
The length of an episode can vary from a few seconds to several minutes.
You'll be able to move and speak as normal afterwards, although you may feel unsettled and anxious about going to sleep again.
When to see your GP
In many cases, sleep paralysis is a one-off and won't happen again. It's not harmful and isn't usually a sign of an underlying problem.
But it's a good idea to see your GP if:
- you experience sleep paralysis regularly
- you feel very anxious about going to sleep or you're struggling to get enough sleep
- you feel very sleepy during the day, or have episodes where you fall asleep suddenly or lose muscle control - these are symptoms of a related sleep disorder called narcolepsy
Your GP can suggest ways to improve your sleep (see Treatments below for more information). If your symptoms are severe, they may refer you to a sleep specialist such as a neurologist.
Causes of sleep paralysis
Sleep paralysis happens when parts of rapid eye movement (REM) sleep occur while you're awake.
REM is a stage of sleep when the brain is very active and dreams often occur. The body is unable to move, apart from the eyes and muscles used in breathing, possibly to stop you acting out your dreams and hurting yourself.
It's not clear why REM sleep can sometimes occur while you're awake, but it has been associated with:
- not getting enough sleep (sleep deprivation or insomnia)
- irregular sleeping patterns - for example, because of shift work or jet lag
- narcolepsy - a long-term condition that causes a person to suddenly fall asleep at inappropriate times
- a family history of sleep paralysis
- sleeping on your back
In many cases, sleep paralysis is a one-off or very occasional event that occurs in someone who is otherwise healthy.
Treatments for sleep paralysis
Sleep paralysis often gets better over time, but improving your sleeping habits and sleeping environment may help.
It can help to:
- get a good night's sleep - most adults need six to eight hours of good quality sleep a night
- go to bed at roughly the same time each night and get up at the same time each morning
- create a sleeping environment that's comfortable, quiet, dark and not too hot or cold
- avoid eating big meals, smoking, or drinking alcohol or caffeine shortly before going to bed
- get regular exercise (but not within four hours of going to bed)
Read more about how to improve your sleep habits.
If your sleep paralysis is particularly severe, a specialist doctor may suggest taking a course of antidepressant medication, such as clomipramine.
These work by altering REM sleep and are typically prescribed at lower doses than when used for depression.
Article provided by NHS Choices