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What Really Happens During Sleep Paralysis and How to Stop It

If you’ve ever felt scared stiff from hallucinations at night, put your fears to rest. Find out what sleep paralysis is, what causes it, and how to stop it.

By Allison Futterman
Dec 20, 2023 8:00 PMDec 20, 2023 9:07 PM
Woman lying in bed wide awake with a sleep problem
(Credit: SvedOliver/Shutterstock)


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Imagine waking up from sleep, opening your eyes, and realizing that you can’t move or speak. You’re overwhelmed with the terrifying sensation of being paralyzed. Some of you don’t have to imagine — it’s all too real for about 8 percent of the general population who suffers from the condition fittingly known as sleep paralysis (SP). 

This phenomenon, often enveloped in mystery and fear, taps into the deepest phase of our sleep cycle and unveils the intricate workings of our brain and body during rest. Learn what sleep paralysis is, what causes it, and how to stop it.

What Is Sleep Paralysis?

Sleep paralysis falls into a group of disruptive sleep-related disorders called parasomnias. These alarming events can happen either when you are falling asleep (hypnogogic) or as you are waking up (hypnopompic), typically rendering people unable to move or speak. 

How Long Does Sleep Paralysis Last?

Episodes can last up to several minutes. Part of what makes sleep paralysis so scary is that people are completely aware of what’s happening to them — and their inability to do anything about it. Records of this phenomenon date back hundreds of years, but SP still remains something of a mystery. Various cultures believe that the condition is caused by black magic, paranormal forces, or mythical monsters. 

Read More: Why Sleep Paralysis Demons Really Visit Us at Night

When Does Sleep Paralysis Happen?

Although much remains unknown about sleep paralysis, a basic scientific understanding does exist. SP occurs during the REM (rapid eye movement), the deepest phase of sleep. 

Why Does Sleep Paralysis Happen?

When we are in REM, our motor neurons are inhibited, paralyzing the body. This is done as a protective measure to keep the body from acting out the intense dreams that occur during this phase of sleep. Since most of us are usually fully asleep during this time, we don’t notice and aren’t disturbed by the paralysis. 

Are You Awake During Sleep Paralysis?

No, you are not awake during sleep paralysis, but you are also not fully asleep as you’re transitioning either into or out of slumber, and are frighteningly aware of the fact that you are unable to move. This leads to panic, as further efforts to move do not work. Rapid and irregular breathing can happen without issue during REM, but with SP, you might feel like you’re struggling to breathe — or even suffocating.

Read More: Why Do We Sleep?

What Causes Sleep Paralysis?

Research reveals that several conditions are linked to sleep paralysis. Understanding the causes of sleep paralysis involves examining various factors, from genetic predispositions to lifestyle choices and environmental influences.

Family History

Sleep paralysis can sometimes run in families, suggesting a genetic component to the condition.

Physical and Mental Health Conditions

Conditions like narcolepsy, panic disorder, and bipolar disorder are linked to sleep paralysis.

Sleep Factors

Factors such as non-restorative sleep, sleep apnea, nightmares, nighttime leg cramps, and changes in sleep schedule can contribute to sleep paralysis.

Stress and Trauma

High levels of stress and traumatic experiences can significantly increase the likelihood of experiencing sleep paralysis

Certain Medications and Substance Use

Some medications can cause sleep paralysis, including SSRIs, tricyclic antidepressants, anticholinesterase inhibitors, beta blockers, and sleep medications, which can cause sleep paralysis due to their effects on REM sleep. Substance use may also be a contributing factor.

Read More: What Are Lucid Dreams, and Are There Any Real Dangers To Them?

Types of Sleep Paralysis Hallucinations

Estimates suggest that 75 percent of Sleep Paralysis involves hallucinations, of which there are three categories

Intruder Hallucinations 

These occur when people feel that a dangerous presence or being is in the room. 

Chest Pressure Hallucinations

These types of hallucinations are self-descriptive, and can lead to a feeling of suffocation. 

Vestibular Motor Hallucinations

Vestibular-motor (V-M) hallucinations can include out-of-body sensations and feelings of movement, such as flying. 

Intruder and chest pressure hallucinations (sometimes referred to as physical assault hallucinations), are highly correlated with fear and historically mistaken as having supernatural origins. However, V-M hallucinations have been associated with sensations of bliss, as well as erotic feelings.

Read More: Why Is That Recurring Nightmare So Terrifying and Can It Be Treated?

The Difference Between Night Terrors and Sleep Paralysis

Sleep paralysis and night terrors are often conflated. While they are both frightening parasomnias, they are two distinct conditions

What Is Sleep Paralysis Like?

With sleep paralysis, a person usually has their eyes open, they are quiet, and they don’t move while it’s happening. It occurs most often near morning, and a person can be easily awakened from this state. 

What Is a Night Terror Like?

Conversely, someone experiencing a night terror will make sounds or scream during the event; it commonly occurs in the early part of sleep (non-REM), and it is difficult to wake the person. Although night/sleep terrors can affect adults (only a little over 2 percent), the condition is much more prevalent in children, occurring in up to 56 percent of young sleepers. 

Read More: Night Terrors: When It's More Than Just a Bad Dream

How to Stop Sleep Paralysis

One study showed that meditation and relaxation helped reduce SP. Participants used the techniques at home and kept a daily journal of the symptoms. Overall, results showed a 50 percent reduction in the number of days that subjects experienced SP and a 54 percent reduction in the total number of episodes. Hallucinations were reduced by 34 percent.

How To Get Out of Sleep Paralysis in the Moment

If you experience sleep paralysis, it's important to remain calm and concentrate on your breathing. Try to initiate movement with a small muscle, like a finger or toe; this small action can help bring an end to the paralysis episode. But overall, simply being aware of what's happening tends to bring you out of it quicker.

Read More: Irregular Sleep Schedules Can Lead to Health Risks

How to Prevent Sleep Paralysis

Other practices people can try include skipping naps, taking a warm bath before bed, sleeping in a cool room, side sleeping, and staying on a regular sleep schedule. If these techniques don’t help, seeing a sleep disorder expert and undergoing a sleep study can be useful in determining if someone has another sleep disorder (such as apnea) that may be contributing to the problem. 

Frequently Asked Questions About Sleep Paralysis

Why Do People Get Sleep Paralysis?

Sleep paralysis occurs when you start to awaken during the Rapid Eye Movement (REM) stage of sleep, where the body is naturally paralyzed to prevent acting out dreams. Factors like irregular sleep schedules, stress, certain medications, and conditions like narcolepsy can disrupt the sleep cycle, increasing the likelihood of this phenomenon.

Why Sleep Paralysis Makes You See Ghosts?

During sleep paralysis, your brain is in a state between wakefulness and dreaming, which leads to vivid hallucinations. These hallucinations, often perceived as ghostly figures or intruders, are products of the dreaming mind being semi-conscious.

Why Does Sleeping on Your Back Cause Sleep Paralysis?

Sleeping on your back may increase the likelihood of sleep paralysis as it can exacerbate breathing difficulties and disrupt sleep, especially in those with sleep apnea, leading to more frequent awakenings during REM sleep.

Are Your Eyes Open During Sleep Paralysis?

During sleep paralysis, you can often open your eyes. This partial awakening, with the body still in REM-induced paralysis, can be a disorienting experience and contribute to the vivid hallucinations.

Can You Get Sleep Paralysis on Your Side?

Yes, sleep paralysis can occur in any sleeping position, although it's more commonly reported when sleeping on the back. The key factor is waking up during the REM stage, not the sleeping position itself.

Can Stress Cause Sleep Paralysis?

Stress is a significant factor that can contribute to sleep paralysis. High stress levels can disrupt normal sleep patterns and increase the likelihood of waking during the REM stage, leading to sleep paralysis.

Is Sleep Paralysis Hereditary?

There is some evidence to suggest that sleep paralysis can have a hereditary component. Families may have a genetic predisposition to sleep disorders, including sleep paralysis, although the specific genetic factors are not fully understood.

Read More: The Importance of Sleep for Your Body

This article was originally published on Oct. 19, 2021 and has since been updated by the Discover staff.

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