Sleep Paralysis


Sleep paralysis generally refers to the experience of waking up and temporarily not being able to move. It can take a couple of seconds to a few minutes to recover movement.

What Is Sleep Paralysis?

Recurrent isolated sleep paralysis is a sleep disorder in which individuals are frequently unable to move the torso, arms, or legs when falling asleep or upon waking up. The paralysis typically resolves quickly, but recurrent episodes of sleep paralysis can cause anxiety or stress.

Estimates of how many people experience sleep paralysis vary widely. A large review estimated that 7.6% of the general population has experienced at least one event of sleep paralysis, and other studies have suggested numbers as high as 40%. Sleep paralysis may be more likely to occur in students or people with other conditions such as an anxiety disorder or another sleep disorder, particularly narcolepsy.

Sleep paralysis is classified as a rapid eye movement (REM) parasomnia, or an unwanted physical sleep behavior that happens during the REM stage of sleep. Other REM parasomnias include nightmare disorder and REM sleep behavior disorder.

What Does Sleep Paralysis Feel Like?

Sleep paralysis is characterized by the inability to move your body. You cannot move your head and limbs and you are unable to speak. However, you are conscious throughout the paralysis and are able to recall the episode. Sleep paralysis usually goes away on its own after a few minutes.

Sleepers who experience an episode of sleep paralysis often feel fear or anxiety during the event, which may also make them feel apprehensive about falling asleep in the future.

Between 25% and 75% of sleepers experience hallucinations during sleep paralysis. Hallucinations differ from nightmares because they occur when the person is awake. Sleep paralysis-related hallucinations may involve physical sensations, visions, sounds, or out-of-body experiences.

Explaining the Sleep Paralysis Demon

A number of cultures and traditions have attributed sleep paralysis and the related hallucinations to a demon or mystical figure. For example:

  • In the folklore of southeastern Brazil, a crone-like figure called the Pisadeira steps on the chests of sleepers.
  • Japanese folklore has the kanashibari, a spirit that can be summoned to suffocate one’s enemies.
  • Inuit tradition says that shamans are responsible for sleep paralysis events when they cast spells on enemies to separate the soul from the body.

Two common types of hallucinations in particular may explain why these cultures associate sleep paralysis with demons. The first type is intruder hallucinations, or the sensation that an evil figure is in the room. During an intruder hallucination, people may also believe they see or hear the intruder.

The second type is incubus hallucinations, characterized by a feeling of pressure as if someone were sitting on the chest. Although most people continue breathing during sleep paralysis, some of the accompanying muscles involved in breathing may be temporarily paralyzed, which likely explains this feeling of suffocation.

Many folkloric representations specify that sleepers are most vulnerable to sleep paralysis demons when sleeping on their back. The International Classification of Sleep Disorders also notes that sleep paralysis occurs more often when back sleeping.

What Causes Sleep Paralysis?

REM sleep is the sleep stage when people typically dream. As a safety measure to prevent sleepers from engaging in physical movements along with their dreams, the body typically paralyzes the arm and leg muscles temporarily during REM sleep. Sleep paralysis is thought to represent a faulty switch in which the part of the brain that controls REM paralysis continues to paralyze these muscles even when the sleeper is awake.

People with certain inherited traits to do with the sleep-wake cycle may be predisposed to develop sleep paralysis. Likewise, sleepers who do not handle disrupted sleep well may be at greater risk for sleep paralysis.

A number of factors that affect the stability of the sleep-wake cycle may trigger sleep paralysis episodes, such as:

  • Sleep deprivation
  • Irregular sleep schedule
  • Jet lag
  • Stress

To qualify as recurrent isolated sleep paralysis, the sleep paralysis episodes cannot be caused by narcolepsy or other sleep disorders, mental or physical health conditions, substance use, or medications.

Is Sleep Paralysis Dangerous?

Sleep paralysis is not life-threatening. However, the episodes can cause anxiety or future worry about falling asleep.

Treating Sleep Paralysis

Sleep paralysis treatment focuses on removing triggers that affect sleep quality. This may include improving sleep hygiene and ensuring you get at least seven hours of sleep each night. When traveling across time zones, you may want to avoid sleeping on your back until your jet lag has resolved.

You can also take preventative measures, such as training yourself to move a finger when you are drowsy. This movement may help stop the onset of a sleep paralysis episode. If you sleep with a bed partner, you can ask them to gently touch you if they hear you murmur in the morning before you wake up.

Cognitive behavioral therapy can help you develop strategies for managing fear and anxiety during hallucinations. Remembering how you successfully ended a previous episode might help you work through a current episode.

Most people do not need to take medication for sleep paralysis, although treating narcolepsy with certain drugs may also reduce sleep paralysis events.

If you are concerned about your experiences with sleep paralysis, talk to your healthcare provider. They can help determine if the episodes might be due to an undiagnosed disorder, and work with you to develop a treatment plan.


+ 9 Sources
  1. 1. Accessed on October 14, 2021.
  2. 2. Accessed on October 14, 2021.
  3. 3. Accessed on October 14, 2021.
  4. 4. Accessed on October 14, 2021.
  5. 5. Accessed on October 14, 2021.
  6. 6. Accessed on October 14, 2021.
  7. 7. Accessed on October 14, 2021.
  8. 8. Accessed on October 14, 2021.
  9. 9. Accessed on October 14, 2021.

Related Reading: