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You wake up in the middle of the night and there it is: a menacing presence that you can first feel and then see when you open your eyes. Scared like the dickens, you try to scream and bolt — but you can’t. It’s like you’re paralyzed or being held down by the evil presence.

What in the world is happening? Three words: sleep paralysis demons.

It’s a thing, and you’re not the only one who’s experienced it. Read on to learn more.

What is this “demon” that leaves you trapped in your body, unable to move or scream? It depends who you ask.

For some it’s a faceless, shapeless presence trying to suffocate them. Others describe it as a creepy old hag with claws. Some see an alien and experience what they believe is a full alien abduction. And for others, the demons look like a dead relative.

Different cultures have different explanations for sleep paralysis demons.

Canadian Inuit attribute the sleep paralysis to spells of shamans. Japanese folklore says it’s a vengeful spirit that suffocates its enemies in their sleep.

In Brazilian folklore, the demon has a name — Pisadeira, which is Portuguese for “she who steps.” She’s a crone with long fingernails who lurks on rooftops in the night, then walks on the chest of people who sleep belly up on a full stomach.

The short is answer… sort of.

The paralysis is real. It’s called sleep paralysis. The phenomenon of ~seeing~ something demon-like while experiencing sleep paralysis is also real. It’s called a hypnagogic or hypnopompic hallucination.

As for the demon itself, it’s not real. We promise.

However, there might be a shred of truth to the belly-up component of the Brazilian fable. It turns out, you’re more likely to experience sleep paralysis demons while sleeping on your back.

While sleep paralysis demons are definitely creepy, the explanation behind them is actually kind of boring.

Sleep paralysis happens when you wake up during the dream phase of sleep. During this period, your brain turns off signals to the rest of your body to keep it from moving or acting out your dreams.

If you suddenly wake up while still in this phase, you’re fully conscious but unable to move.

Sleep paralysis

It’s estimated that anywhere from 1.7 percent to 40 percent of people experience sleep paralysis, but not everyone gets the demon experience. That’s because not everyone experiences sleep paralysis alongside hypnagogic or hypnopompic hallucinations.

Hypnagogic and hypnopompic hallucinations

Vivid dream-like experiences, referred to as hypnagogic or hypnopompic hallucinations, can seem real and are often frightening. They may be mistaken for nightmares, and they can occur while you’re falling asleep (hypnagogic) or waking up (hypnopompic).

During these hallucinations, you may see scary people or creatures near you or even lying in your bed. And they’re often accompanied by sleep paralysis.

These hallucinations can happen if you’re partially conscious during the rapid eye movement (REM) cycle of sleep. In that state, you’re looking at the real world but also dreaming — the prefect recipe for seeing things that aren’t really there.

You might also see a distortion of something that really is there. For instance, the pile of clothes on your chair could turn into a person sitting there watching you sleep, or the light from your alarm clock could morph into a red-eyed monster.

When you sleep on your back, you may be more likely to be aroused from sleep or wake up during the dream phase, due to things like snoring and undiagnosed obstructive sleep apnea.

The following can also increase your chances of experiencing sleep paralysis and hypnagogic or hypnopompic hallucinations:

Knowing that sleep demons aren’t real and that episodes of sleep paralysis generally don’t last for more than a minute — even if they feel like a lifetime — can help ease some of your stress about them.

Here are some other tips to help you reduce your chances of experiencing these episodes:

  • Adopt a healthy sleep schedule. Go to bed and get up at the same time every day, and aim for 6 to 8 hours of sleep each night.
  • Improve your bedtime routine. Take a cue from the Pisadeira story and avoid going to sleep on a full stomach. Refrain from having caffeine and alcohol close to bedtime. Doing something relaxing before bed can also help you get a good night’s sleep.
  • Don’t sleep on your back. Sleep paralysis is more likely to happen when you sleep on your back since you’re more likely to be awoken from snoring or sleep apnea, so opt for any other position that’s comfortable. If you have the tendency to end up on your back even after falling asleep in another position, placing a pillow on either side can stop you from rolling over all the way.
  • Treat any underlying conditions. Stress, anxiety disorders, and other mental health conditions can contribute to frequent episodes of sleep paralysis. Treating the underlying cause can help prevent these episodes.
  • Talk with your doctor about medications you take. Side effects from certain medications can lead to sleep issues, including vivid dreams, nightmares, and sleep paralysis. If your episodes started or increased after starting a new drug or you think your medication could be to blame, talk with your healthcare provider.
  • Exercise regularly. Regular exercise can reduce stress and anxiety and improve sleep. Just avoid working out too close to bedtime.
  • Use relaxation techniques. Deep breathing, meditation, and yoga are just some relaxation techniques that can help you de-stress before bed to keep stress — and sleep demons — at bay.

Also, be aware of lucid dreaming. This often occurs with sleep paralysis.

A lucid dream is when you’re aware of your consciousness during a dream. During a lucid dream, you’re able to take control of what happens in your dream.

Most people have had a lucid dream at one time or another.

Sleep paralysis demons may not be real, but that doesn’t make the experience of being trapped in your body with the sense or vision of one any less terrifying.

If you have frequent episodes or are finding them to be anxiety-inducing and disruptive to your daily life, talk with your healthcare provider.


Adrienne Santos-Longhurst is a Canada-based freelance writer and author who has written extensively on all things health and lifestyle for more than a decade. When she’s not holed up in her writing shed researching an article or off interviewing health professionals, she can be found frolicking around her beach town with husband and dogs in tow, or splashing about the lake trying to master the stand-up paddleboard.