What’s a Sleep Paralysis Demon?

Find out what’s really going on when you have a "visit" from a scary nighttime creature, plus tips on how to cope.

High Angle View Of Woman Sleeping On Bed With Spooky Shadow On Wall At Home
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You’re sleeping when suddenly something is smothering you. You attempt to get free but can’t move your arms or legs. An evil entity has pinned you beneath its crushing weight.

If this sounds terrifyingly familiar, you’ve likely had a visit from a “sleep paralysis demon.” Though it sounds like it came straight out of a horror movie, sleep paralysis with the hallucination of a demon is a reality for an estimated 8% of the population. Some studies found the spooky experience even more common, with 30% of people reporting at least one incident in their lifetime.

What is a sleep paralysis demon?

A sleep paralysis demon is a hallucination that occurs when you’re transitioning out of sleep. During the lifelike dreams of rapid eye movement (REM) sleep, your voluntary muscle movements are immobilized so that you don't act out your dreams. Most of the time, this so-called paralysis is helpful, but occasionally, your brain becomes somewhat awakened during the transition from REM to wakefulness.

During this period, you may sense or even see a malevolent presence lurking nearby or hovering over you. You may also feel as if the presence is pressing down on your chest or somehow attacking you. That is a sleep paralysis demon.

Understandably, the experience can be terrifying. In such a vulnerable and not fully aware state, it can be hard to differentiate hallucination from reality. But rest assured, you are not starring in your own horror show. The mind is a fascinating thing, and sometimes, it plays tricks on us, giving us the fright of our lives. Keep reading to find out the science behind what’s happening in the brain during this frightening phenomenon and what you can do to prevent the situation from happening again.

Sleep demon depictions across cultures

The so-called sleep paralysis demon — which can manifest as a witch, evil spirit, or other creature — isn’t new or isolated to a specific region. Many cultures refer to the condition as the “incubus phenomenon.” The term “incubus” is Latin for night hag or nightmare. Ancient Greek culture even gendered the demons, with incubus referring to a demon disguised as a man pressing down on a sleeping woman and succubus describing a demon disguised as a woman pressing down on a sleeping man.

Incubi and succubi have been referenced for hundreds of years and have countless names. More than 100 cultures have their own descriptions, many of which align with regional folklore, for the unsettling experience of sleep paralysis. Here are a few.

  • One early reference to sleep paralysis stems from about 400 BC, in ancient Greece, where references are found to “Pan ephialtes,” a horned god that could “pounce upon someone” in their dreams. 
  • Another early reference to a succubus harkens back to 2400 BC, when a “she-demon” was called “Lilith” or “Lilitu,” stemming from Mesopotamian and Jewish mythology. 
  • In Catalan folklore, the demon is more like a malevolent dog or cat called “Pesanta,” known for breaking into houses at night where it “steps over people’s chests, disturbing their breath and causing nightmares.” 
  • In Korean culture, ‘Ha-wi-nulia” roughly translates to “being squeezed by scissors.” 
  • In Newfoundland, the sleep paralysis phenomenon is called Old Hag. The assailant is said to be an old hag “who can put it on you like a charm.” 
  • In Brazil, “Pisadeira” is the hallucinated entity, which folklore describes as a long-fingernailed crone who “tramples on the chest of those who sleep on a full stomach with the belly up.” 
  • The Dutch have referred to the demon as the “Night-Mare.” 
  • Olde English features the word “mære,” referencing a female spirit who suffocates people in their sleep. 
  • In Germany, the term is “hexendrücken,” which means “witch’s pressing.” 
  • In France, people call the demon “cauchemar.” 
  •  In Southeast Asia, people fear the “dab tsog,” a nightmare spirit. 
  • The Yoruba people of Nigeria call the experience “ogun oru,” which translates to “nocturnal warfare.” This term is also used for epileptic seizures. 
  • In Egypt, the spiritual creature is known as a “Jinn.”  
  • In Japan, the sleep paralysis phenomenon gets the term “kanashibari,” translating to “bound in metal.” 
  • Mexico calls the experience “Se me subió el muerto,” translating to “a dead body climbed on top of me.” 
  • In Iran, the experience is called “Kabus,” or a heavy presence lurking on one’s chest, causing breathing difficulty. 
  • The Inuit People in the subarctic regions of Canada refer to the horror as “uqumangirniq,” in which shamans are responsible for casting spells on people who sleep. 
  • Cambodian people have called the imaginary entity “khmaoch sângkât” or “the ghost that pushes you down.”  
  • In Thailand, “phi am” is a “ghost that haunts subjects when half-asleep and unable to move.” 
  • In Saint Lucia, the term is “Kokma,” which is described as “attacks by dead spirits or unbaptized babies that jump into a body and squeeze the throat.” 
  • In Ethiopia, the evil spirit that haunts you in your sleep is called “dukak.” 
  • In the Tanzanian archipelago Zanzibar, “Popobawa” is the evil entity. 
  • In the United Kingdom, a myth says that a spirit is trying to get into your body during sleep, but it fails to do so while you’re waking. 

Often, sleep paralysis is mentioned as a way of explaining the unexplained, such as paranormal activity or even alien abductions. Sleep paralysis demons appear in art, including “The Nightmare,” an 18th-century painting by Swiss artist Henry Fuseli, and works by Francis Bacon and Francisco Goya.

The demon has also been a common theme of television shows, such as “American Horror Story,” and countless novels and movies. The 2018 horror movie “Mara,” directed by Clive Tonge, depicts a criminal psychologist who is investigating the murder of a man in his sleep. She then experiences the haunting of a sleep-paralysis demon herself.

Are these demons real?

Although the many detailed, disconcerting folklore descriptions of the sleep paralysis demon are detailed, they are not real. The intruding sleep paralysis demon, in all cases, is nothing more than a hallucination that occurs as you’re transitioning out of sleep. However, the momentary paralysis is real. Although scary, the phenomenon results from your brain temporarily pausing during the transition from REM sleep to an awakened state.

What is sleep paralysis?

In simple terms, sleep paralysis is a medical condition where you’re stuck in a state somewhere between sleep and wakefulness. In this state, you will have some awareness of your surroundings, though you’re still experiencing the muscle paralysis of REM sleep, which renders you unable to move.

When we sleep, we go through several sleep cycles — usually four to six — per night, with each cycle broken into four phases. The first three phases of sleep are non-REM, while the final phase is REM, which takes increasingly more time in each cycle as you progress toward wake-up. So, while it’s possible to experience sleep paralysis in the middle of the night, it’s most common in the morning. Episodes that occur in the middle of the night are often attributed to sleep disruptions that awaken you from REM and prevent you from moving into your next sleep cycle.

Often, sleep paralysis is coupled with hallucinations because of the transition from dream to reality. Sometimes, the brain experiences a glitch when flipping the switch on how it processes information during this transition. Disorienting and even terrifying hallucinations can occur even if you weren’t previously having a nightmare.

Sleep paralysis

Much of the powerless feeling of sleep paralysis comes from the physical nature of the experience — the inability to move our muscles in the moment to react to the situation.

During REM sleep, which is the last phase of each sleep cycle, we tend to dream. So that we do not enact our dreams, our brain essentially paralyzes our muscles during this phase, suppressing muscle tone and inhibiting the neurons in the spinal cord.

Eventually, we transition from REM sleep to being awake and aware. However, sleep paralysis occurs when you gain some awareness of your surroundings mentally but are still physically motionless due to the paralyzing effects of the REM phase. Think of it like transitioning spaces: You are midway through exiting one room (REM sleep) but have not yet fully entered the next (being awake).

Sleep hallucinations of demons

We’re all prone to visual, auditory, and sensory hallucinations, both when we’re falling asleep and when we’re waking up. When it comes to symptoms of sleep paralysis, this can include a sense that an intruder is near you — a hallucination.

Hypnagogic hallucinations occur when we’re slipping into the first phase of sleep, which is non-REM (NREM). You might see a kaleidoscope of colors or patterns, for example, or you might experience a sense of falling and then accidentally jerk yourself awake, a phenomenon called hypnic jerks. Hypnopompic hallucinations, on the other hand, occur when we’re waking up and transitioning out of REM sleep; they are often continuations of dreams.

A sleep paralysis demon is a hypnopompic hallucination. The demons often take the shape of childhood fairytale villains, such as witches, ghosts, beasts, or other ominous creatures.

Though more research is needed to understand exactly why people so commonly hallucinate seeing demons, researchers theorize that people see a humanoid figure over them because of a momentary lapse in how the brain processes bodily perception. When we’re awake, the parietal lobe sends us information about our body parts and their positions and movements. This info helps us understand where we are in relation to objects, so we don’t constantly bump into doorframes or coffee tables, for example. During sleep paralysis hallucinations, that valuable info called proprioception and other sensory input gets muddled, and we see a highly distorted projection of our brain’s stored body image. It’s like we’re looking into a mirror but seeing a monster.

Fear gets amplified in this state. The intense terror likely occurs because the amygdala, known as the fear center of the brain, is highly activated during REM sleep. The hyperactivity of the amygdala is why dreams can be so intense. Throughout the waking day, if you encounter a potential threat, you can quickly assess whether the threat is legitimate and react accordingly, thanks to your brain’s logic-regulating abilities of the pre-frontal cortex, which is dormant while you sleep. But during REM sleep, your brain lacks the information to correctly assess whether a threat is real. So, during a “visit” from a sleep paralysis demon, nothing reassures you that it’s only a dream.

How sleep paralysis demons affect sleep

Although the demon itself is not real, the experience of hallucination of a sleep paralysis demon can be horrifying enough to have lasting effects on your sleep. If you endure the sleep paralysis demon phenomenon often, you may understandably develop a fear of going to bed, which could then lead to insomnia and even long-term anxiety. Both insomnia and anxiety are associated with experiencing sleep paralysis demons.

Additionally, enduring this type of terror in the middle of the night can cause disrupted sleep, breaking up your transition to your next sleep cycle and keeping you awake if you’re unable to fall back asleep.

Common symptoms of sleep paralysis demons

Symptoms of the sleep paralysis demon phenomenon are somewhat different for each person who experiences it. Symptoms However, some commonalities exist, such as:

  • being terrified 
  • feeling immobilized or unable to move 
  • seeing a demon or entity 
  • sensing a presence on the chest 
  • feeling like you can’t breathe 
  • smelling an odor 
  • hearing strange sounds 
  • experiencing the sensation of choking 
  • experiencing chest pain and discomfort 
  • experiencing heart palpitations 
  • experiencing numbness or tingling 
  • feeling cold or hot 
  • having abdominal pain or an upset stomach 
  • feeling dizzy, lightheaded, or as if you’re spinning 
  • sweating 
  • shaking 

Why is there a demon in my room? Causes of sleep paralysis and hallucinations

Anyone can experience sleep paralysis. But, a systematic review that looked at 42 studies on the topic found common themes among people who have reported episodes of the phenomenon.

You may be more prone to sleep paralysis when one or more of these factors are present:

  • alcohol  
  • anti-anxiety medication 
  • chronic pain 
  • family history of sleep paralysis 
  • history of childhood sexual abuse 
  • loss of a loved one 
  • mood disorder 
  • Narcolepsy 
  • nicotine 
  • paranormal beliefs 
  • post-traumatic stress disorder (PTSD) 
  • poor quality sleep 
  • physical illness 
  • sleep disruptions 
  • survival of an assault 
  • survival of a disaster 
  • trauma 

Researchers do not yet know the reasons some people experience the sleep paralysis demon phenomenon while others do not. This list, though, surfaces a few common themes. People experiencing mental health issues — such as anxiety disorder, panic disorder, and PTSD — may have a predisposition to experiencing a sleep paralysis demon. This may be due to a REM sleep behavior disorder (RBD), which could lead to hallucinations.

People with these disorders may be in what’s called a hypervigilant state during waking hours, where the body is subconsciously always monitoring for a threat. This can alter levels of neurotransmitters. During REM sleep, the brain is highly active. It often calls up difficult memories, processes them and then removes their emotional charge. However, for people with PTSD, for example, altered levels of neurotransmitters may prevent the brain from tamping down the emotional charge, leading to an overwhelming sense of fear. More research is needed to see if this phenomenon is also linked to sleep hallucinations.

Sleep disorders and disrupted sleep are also common features among people who experience sleep paralysis demon. Substances, medications, noise at night, light pollution, and more can all disrupt sleep. Sleep disruptions interrupt our natural sleep phases and cycles, which may then lead to that snagging between REM sleep and an awakened state.

How to stop an episode of sleep paralysis in the moment

Limited research exists on what you can do in the moment to stop sleep paralysis, but if the phenomenon occurs regularly, you can try to train your mind with a few techniques to halt or bypass the terror.

  • First, remind yourself, if possible, that the demon isn’t real and that you are safe. 
  • Take slow, deep breaths to calm yourself. 
  • Try to gently move your arms or legs or turn on your side. Often, the issue occurs when sleeping on your back, so turning may help if you are able to do so. 
  • Call out, if possible. This can signal the brain to wake up fully. 
  • Blink your eyes, if possible. Again, this might signal the brain to wake up. 

Coping strategies to prevent sleep paralysis demons

There is no current direct treatment for sleep paralysis or a specific way to banish the hallucinated demon. Instead, treatments often focus on potential underlying causes. Here are a few considerations.

If you are experiencing frequent disruptions in your slumber, try improving your sleep hygiene. Improving your sleep habits and sleep space may help you get through more sleep cycles without interruption and prevent you from awakening mid-REM sleep.

If you’re struggling with anxiety or stress or recovering from trauma, seek help from a mental health professional who can help you address those concerns. Research indicates cognitive behavioral therapy (CBT) may be of benefit.

Some research suggests that episodes of sleep paralysis may create a feedback loop that leads to more intense episodes, fueling the phenomenon. Baland Jalal, Ph.D., a neuroscientist who is a Harvard University researcher studying sleep paralysis, suggests a four-step approach for tamping down that fear just after an episode.

  • After an episode has passed, think about how it was temporary, not real, and caused by a hiccup at the transition between REM sleep and an awakened state. 
  • Remind yourself that the experience happens to other people, and there is no reason to be afraid; fear can be counterproductive. 
  • Meditate inward by focusing on something positive, like a loved one, a favorite mantra, or a nice memory. Avoid thinking about physical sensations or the environment around you. 
  • Continue to meditate and add in muscle relaxation by avoiding any tensing or flexing. 

You can also practice the process even when sleep paralysis has not occurred so that it’s a skill you have at the ready.

FAQs about sleep paralysis

Can sleep paralysis demons be prevented?

Some techniques, such as treating underlying sleep disorders, improving sleep hygiene, and undergoing cognitive behavioral therapy may help prevent sleep paralysis.

Is sleep paralysis dangerous?

Although the experience of sleep paralysis is real, if you see a demon, it is only a hallucination. So, the phenomenon is not dangerous. However, long-term health issues, such as high blood pressure, may arise if you experience anxiety or sleep deprivation from the issue.

How long does sleep paralysis last?

Sleep paralysis typically only lasts for a few seconds or minutes.

How common is sleep paralysis?

Sleep paralysis occurs in 8% to 30% of the population.

When to seek professional help

If you continue to experience sleep paralysis episodes, talk to your health care provider. They may be able to help you find a solution.

Although they feel real, these monsters are just a cruel trick of the brain. Sleep paralysis demons are understandably scary, but you’re not being haunted or attacked. And you’re not losing your grip on reality, either. The key to making this experience less scary is to take a deep breath and remember it’s a glitch in your sleep cycle.