Sleep Paralysis: Causes, Symptoms & Treatment
People may wake in the middle of the night and find themselves unable to move or utter a sound. These bizarre experiences are known as sleep paralysis, a diagnosable and fairly common sleeping disorder.
Although sleep paralysis can result in high levels of anxiety, it isn’t generally considered life-threatening. While more research is needed on the long-term effects, episodes usually only last between a few seconds and a few minutes.
Sleep paralysis is a temporary loss of muscle function while you’re sleeping. It typically occurs as a person is falling asleep, shortly after they have fallen asleep, or while they’re waking up. According to the American Academy of Sleep Medicine, those with sleep paralysis usually experience this condition for the first time between the ages of 14 and 17 years old. It is a fairly common sleep condition. Researchers estimate it occurs in anywhere between 5 and 40 percent of people.
According to a 2011 review, about 7.6% of the world’s population experiences at least one episode of sleep paralysis in their lifetime, with higher rates noted among students and psychiatric patients, particularly those with post-traumatic stress or panic disorder. Sleep paralysis is a condition characterized by excessive sleepiness, sleep attacks and sudden loss of muscle control, as described by the National Sleep Foundation.
Symptoms Of Sleep Paralysis?
Sleep paralysis isn’t a medical emergency. Being familiar with the symptoms can provide peace of mind. The most common characteristic of an episode of sleep paralysis is the inability to move or speak. An immobility episode may last for a few seconds to about two minutes.
Episodes typically end on their own, or when another person touches or moves you. You may be aware of what’s happening but still unable to move or speak during an episode. You also may be able to recall the details of the episode after temporary paralysis disappears. In rare cases, some people experience dreamlike hallucinations that may cause fear or anxiety, but these hallucinations are harmless. Sleep paralysis can even occur in people who don’t have narcolepsy.
Narcolepsy also can be associated with other sleep disorders, such as obstructive sleep apnea, restless legs syndrome, and insomnia.
What Causes Narcolepsy?
The exact cause of narcolepsy is unknown. However, most people with narcolepsy and cataplexy have a decreased amount of a brain protein called hypocretin. One of the functions of hypocretin is regulating your sleep-wake cycles.
Scientists think low hypocretin levels may be caused by several factors. A gene mutation has been identified that causes low levels of hypocretin. It’s believed that this hereditary deficiency, along with an immune system that attacks healthy cells, contributes to narcolepsy. Other factors such as stress, exposure to toxins, and infection also may play a role.
How Is Narcolepsy Diagnosed?
The Center for Narcolepsy at the Stanford University School of Medicine reports that one in every 2,000 Americans has narcolepsy. If you have excessive daytime sleepiness or one of the other common symptoms of narcolepsy, talk to your doctor. Daytime sleepiness is common in many types of sleep disorders. Doctors usually require a sleep study and several other tests to determine the correct diagnosis.
Some common sleep evaluations include the following:
- The Epworth Sleepiness Scale (ESS) is a simple questionnaire. It asks how likely you are to sleep in different circumstances.
- ActiGraph, or other home monitoring systems, can keep track of how and when you fall asleep. This device is worn like a wristwatch and may be used together with a sleep diary.
- Polysomnogram (PSG) testing requires that you spend the night in a medical facility. You’ll be monitored while you sleep with electrodes attached to your scalp to measure brain activity, heart rate and rhythm, eye movement, muscle movement, and breathing. This test can also detect sleep apnea.
- A multiple sleep latency test (MSLT) determines how long it takes you to fall asleep during the day. It also looks at how quickly you enter REM sleep. This test is often given the day after a polysomnogram. You’ll need to take four to five naps throughout the day, each two hours apart.
- A spinal tap, or lumbar puncture, is used to collect cerebrospinal fluid (CSF) to measure hypocretin levels. Hypocretin in CSF is expected to be low in people with narcolepsy. For this test, your doctor will insert a thin needle between two lumbar vertebrae.
Prevalence Through History
References to sleep paralysis are scattered throughout history, though not usually under the name “sleep paralysis.” Folklore and myths from around the world describe the terrifying experience of being unable to move upon waking and sometimes seeing beings, being choked or being held down. Nightmares known as the “Old Hag” in Newfoundland, Kokma in St. Lucia, and tsog in East Asia may have all be borne of the same spooky experience, according to an article in the Journal of the Royal Society of Medicine. In 1664, a Dutch physician described a patient’s experience of sleep paralysis as the “Incubus or the Night-Mare,” providing the first known clinical description of the affliction.
Are Sleep Paralysis Demons Attack Or Hallucinations?
Sleep paralysis arises from disrupted REM sleep, named for the rapid eye movements that occur during this stage of the sleep cycle. [Can You Learn Anything While Sleeping Deep?]
“During sleep paralysis, you have two aspects of REM sleep going on when you’re awake,” said Brian Sharpless, a licensed clinical psychologist and co-author of the book “Sleep Paralysis: Historical Psychological, and Medical Perspectives” (Oxford University Press, 2015). You’re most likely to experience dreaming during REM sleep, he said, and the body actually becomes paralyzed “presumably so you don’t try to act out your dreams.”
People who have experienced sleep paralysis often describe sensing an evil presence, or demon in the room with them. A study published in the journal Sleep Medicine last month reported that out of 185 patients diagnosed with sleep paralysis, about 58% sensed a presence in the room with them, usually something non-human, and about 22% actually saw a person in the room, usually a stranger.
Sometimes people find the out-of-body hallucinations pleasant and feel as though they’re weightless, but more often, the sensations can be quite disturbing. Like paralysis, these hallucinations may also be a lingering manifestation of REM sleep.
“We know the amygdala is highly active in REM, which is important to fear and emotional memory,” said Daniel Denis, a postdoctoral scholar in psychiatry at the Beth Israel Deaconess Medical Center in Boston. “You have part of the brain actively responding to fear or something emotional, but nothing in the environment to account for that. So the brain comes up with a solution to that paradox.” That’s one possible explanation, he said; but the actual cause of the hallucinations is still unknown.
Risk Factors And Treatment
A myriad of factors, including substance use, genetic factors, a history of trauma, a psychiatric diagnosis and poor physical health and sleep quality, may increase the risk of developing sleep paralysis, according to a 2018 review. The frequency and severity of episodes has also been linked to anxiety-like symptoms and sleep deprivation.
There is no set treatment for sleep paralysis, but doctors usually direct diagnosed patients to improve their sleep schedule and maintain a better bedtime routine. In more extreme cases, patients may be prescribed a low dose of antidepressants, according to the National Health Society of the UK. These medications may help mitigate mediate the symptoms of sleep paralysis by suppressing certain aspects of REM sleep.
What Should One Do If You Experience Sleep Paralysis?
“If you have rare episodes of sleep paralysis, but haven’t been seen by a sleep specialist, make sure your sleep hygiene is solid,” said Shelby Harris, director of Behavioral Sleep Medicine at the Sleep-Wake Disorders Center at the Montefiore Health System in the Bronx, New York City. “For example, sleep paralysis can be a sign that you’re sleep deprived,”
Harris suggested that people experiencing sleep paralysis should:
- Make sure to get enough sleep on a regular basis
- Avoid alcohol, nicotine and drugs all night
- Exercise regularly. This can help you rest better at night and keep you alert during the day.
- Maintain a healthy weight. Researchers have found an association between narcolepsy and being overweight.
- Also limit caffeine after 2p.m. and keep electronics out of the bedroom.
If you have a mental disorder such as anxiety or depression, taking an antidepressant may diminish episodes of sleep paralysis. Antidepressants can help reduce the amount of dream sleep you have, which lessens sleep paralysis, according to the American Association of Sleep Medicine.
- Learn more about sleep paralysis from the University of Washington Medicine’s “Right as Rain.” Here’s another perspective from UW Medicine.
- Read more about narcolepsy from the Mayo Clinic.
- Learn more about other conditions that may cause hallucinations from Healthline.