While the states of sleep and wakefulness are usually clearly defined and distinct, conditions like sleep paralysis can challenge these fixed boundaries.
Sleep paralysis is a temporary inability to move that occurs directly after falling asleep or waking up. Individuals maintain awareness during episodes, which frequently involve troubling hallucinations and a sensation of suffocation.
Episodes of sleep paralysis involve elements of both sleep and wakefulness, which is partly why they can lead to distressing symptoms.
While much is still unknown about sleep paralysis, learning about types, symptoms, causes, impacts, and treatment can enable a better understanding of the condition and ways to prevent it.
What Is Sleep Paralysis?
Sleep paralysis is a condition identified by a brief loss of muscle control, known as atonia Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference , that happens just after falling asleep or waking up. In addition to atonia, people often experience hallucinations during episodes of sleep paralysis.
Sleep paralysis is considered a parasomnia. Parasomnias are abnormal behaviors during sleep. Because it is linked to the rapid eye movement (REM) stage of the sleep cycle, sleep paralysis is considered to be a REM parasomnia.
Standard REM sleep involves vivid dreaming along with atonia, which usually helps prevent acting out dreams. Atonia typically ends upon waking up, so a person never becomes conscious of this inability to move.
As a result, researchers believe that sleep paralysis involves a mixed state of consciousness Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference that blends both wakefulness and REM sleep. In effect, the atonia and mental imagery of REM sleep seems to persist even into a state of being aware and awake.
What Are the Types of Sleep Paralysis?
Medical experts commonly use two terms to categorize cases of sleep paralysis Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference .
- Isolated sleep paralysis: These episodes are not connected to an underlying diagnosis of narcolepsy, a neurological disorder that prevents the brain from properly controlling wakefulness, which often leads to sleep paralysis.
- Recurrent sleep paralysis: This condition involves multiple sleep paralysis episodes over time.
In many cases, these two defining characteristics are combined to describe a condition called recurrent isolated sleep paralysis (RISP), which involves ongoing instances of sleep paralysis in someone who does not have narcolepsy.
What Does Sleep Paralysis Feel Like?
The defining symptom of sleep paralysis is atonia, or the inability to move the body.
An estimated 75% of sleep paralysis episodes also involve hallucinations that are distinct from typical dreams. As with atonia, these can occur when falling asleep (hypnagogic hallucinations) or waking up (hypnopompic hallucinations).
Hallucinations during sleep paralysis fall into three categories.
- Intruder hallucinations: These hallucinations involve the perception of a dangerous person or presence in the room.
- Chest pressure hallucinations: Also called incubus hallucinations, these episodes may incite feelings of suffocation. These frequently occur in tandem with intruder hallucinations.
- Vestibular-motor (V-M) hallucinations: V-M hallucinations can include feelings of movement, such as flying, or out-of-body sensations.
Does Sleep Paralysis Have a Meaning?
The perception of sleep paralysis episodes has been found to vary significantly based on a person’s cultural context Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference . Atonia is often distressing, and troubling hallucinations can make episodes even more disturbing. For this reason, around 90% of episodes are associated with fear while only a minority have more pleasant or even blissful hallucinations.
Episodes can last from a few seconds to around 20 minutes, and the average length Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference is between six and seven minutes. In most cases, episodes end on their own but occasionally are interrupted by another person’s touch or voice, or by intense effort to move that overpowers atonia.
How Common Is Sleep Paralysis?
Prevalence varies, but researchers believe that about 20% of people Trusted Source UpToDate More than 2 million healthcare providers around the world choose UpToDate to help make appropriate care decisions and drive better health outcomes. UpToDate delivers evidence-based clinical decision support that is clear, actionable, and rich with real-world insights. See Full Reference experience sleep paralysis at some point in their life. There is little data among this group about how often episodes recur.Sleep paralysis can occur at any age Trusted Source National Institutes of Health (NIH) The NIH, a part of the U.S. Department of Health and Human Services, is the nation’s medical research agency — making important discoveries that improve health and save lives. See Full Reference , but first symptoms often show up in childhood, adolescence, or young adulthood. After starting during teenage years, episodes may occur more frequently in the 20s and 30s.
What Causes Sleep Paralysis?
The exact cause of sleep paralysis is unknown. Studies have analyzed data to determine what heightens one’s risk of sleep paralysis, and have found mixed results. Based on those findings, researchers believe that multiple factors are involved in the onset of sleep paralysis.
Sleep disorders and other sleeping problems have shown some of the strongest correlations with isolated sleep paralysis. Higher rates of sleep paralysis — 38% in one study Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference — are reported by people with obstructive sleep apnea (OSA), a sleep disorder marked by repeated lapses in breathing. Sleep paralysis also has been found to be more common in people with nighttime leg cramps.
Insomnia symptoms like having a hard time falling asleep and excessive daytime sleepiness have been found to be linked with sleep paralysis. People whose circadian rhythms are not aligned with their local day-night cycle, such as people with jet lag and shift workers, may also be at higher risk of sleep paralysis.
Certain mental health conditions have shown a connection Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference to sleep paralysis. People with anxiety disorders, including panic disorder, appear to be more likely to experience the condition. Some of the strongest associations are in people with post-traumatic stress disorder (PTSD) and others who have been exposed to physical and emotional distress. Stopping alcohol or antidepressants can lead to REM rebound, which may also cause sleep paralysis.
Studies have found a higher risk in people with a family history of sleep paralysis, but no specific genetic basis has been identified.
Some studies have found that people who show traits of imaginativeness and disassociation Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference from their immediate environment, such as daydreaming, are more likely to experience sleep paralysis. There may be a link as well between sleep paralysis and vivid nightmares or lucid dreaming.
Further research is necessary to investigate these correlations and better understand the numerous potential causes of sleep paralysis.
Is Sleep Paralysis Dangerous?
For most people, sleep paralysis is not considered dangerous. Though it may cause emotional distress, it is classified as a benign condition and usually does not happen frequently enough to cause significant health effects.
However, an estimated 10% of people have more recurrent or bothersome episodes that make sleep paralysis especially troubling. As a result, they may develop negative thoughts about going to bed, reducing time allotted for sleep or provoking anxiety around bedtime that makes it harder to fall asleep. Sleep deprivation can lead to excessive daytime sleepiness and numerous other consequences for a person’s overall health.
What Are the Treatments for Sleep Paralysis?
A first step in treating sleep paralysis is speaking with a doctor in order to identify and address underlying problems that may be contributing to the frequency or severity of episodes. For example, this could involve treatment for narcolepsy or steps to better manage sleep apnea.
Overall, there is limited scientific evidence about the most effective treatment for sleep paralysis. Many people are unaware that the condition is relatively common and thus feel ashamed after episodes. As a result, even just an acknowledgment and normalization of their symptoms by a doctor can be beneficial.
Because of the connection between sleep paralysis and general sleeping problems, improving sleep hygiene is a common focus in preventing sleep paralysis.
There are a number of sleep hygiene techniques that can contribute to better sleep quality and more consistent nightly rest.
- Establish a routine: Follow the same schedule for going to bed and waking up every day, including on weekends. A soothing pre-bed routine can help you get comfortable and relaxed.
- Optimize your sleep space: Outfit your bed with the best mattress and best pillow for your needs. It is also useful to design your bedroom to have limited intrusion from light or noise.
- Curb substance use: Reduce alcohol and caffeine intake, especially in the evening.
- Remove distractions: Put away electronic devices, including cell phones, for at least an hour before bed.
Improving sleep hygiene is frequently incorporated into cognitive behavioral therapy for insomnia (CBT-I), a type of talk therapy that works to reframe negative thoughts and emotions that detract from sleep.
A specific form of CBT has been developed for sleep paralysis Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference , but more research is needed to validate its effectiveness. CBT has an established track record Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. See Full Reference in addressing mental health conditions like anxiety and PTSD that may be factors influencing the risk of sleep paralysis.
Some medications are known to suppress REM sleep Trusted Source Medline Plus MedlinePlus is an online health information resource for patients and their families and friends. See Full Reference , and these may help to stop sleep paralysis. These medications can have side effects, and may cause a rebound in REM sleep when someone stops taking them. For these reasons, it is important to talk with a doctor before taking any medication in order to discuss its potential benefits and downsides.
