The sleep paralysis demon: what is really in the room

What is sleep paralysis?

During REM sleep, the stage when most vivid dreams happen, your brain switches off most of your muscles so you do not act out your dreams. Normally that switch flips back before you become aware. In sleep paralysis, the timing slips: your mind wakes up while your body is still locked in REM paralysis. You are conscious, your eyes may be open and you can see your room, but you cannot move or speak, sometimes for seconds and sometimes for a minute or two.

Sleep paralysis can happen as you fall asleep or as you wake up. It is common: a 2011 review by the psychologists Brian Sharpless and Jacques Barber, pooling dozens of studies, estimated that close to 8 percent of people have had at least one episode, with rates several times higher among students and psychiatric patients. On its own it is harmless. What makes it unforgettable is what often comes with it.

The signs are easy to recognize once you know them: you are awake and aware of your real room, you cannot move your arms, legs or head, you cannot speak or scream, your breathing feels shallow or blocked, and you have a strong sense of dread. Your eyes can usually move, which is why you can look around. Many people also see, hear or feel something that is not there, and that is where the demon comes in.

What does a sleep paralysis demon look like?

People describe a small set of figures again and again, across countries and generations. None of them is a sign that something specific is after you. They are the shapes a frightened, half-dreaming brain reaches for first.

• ✦A shadow person: a tall, dark, human outline, often standing at the foot of the bed or in the doorway.
• ✦The hat man: a shadow figure in a brimmed hat or long coat, one of the most widely reported forms online.
• ✦The old hag: a thin old woman sitting on the chest or bending over the bed, the figure behind many folk names.
• ✦A faceless or hooded figure that watches without moving, sometimes with glowing or very dark eyes.
• ✦An animal or creature on the chest: a cat, a dog, a crouching beast, or something with too many limbs.
• ✦No figure at all: just footsteps, whispers, breathing or a voice saying your name, with an overwhelming sense of being watched.

Why do people see a demon?

Because REM sleep has not fully let go, dream imagery can spill into the waking scene. Your brain is also on high alert: you are helpless, in the dark, and your threat detection is firing. Put those together and the mind does what it is built to do, it finds the threat. That is why the figure is so often menacing, and so often the same across very different people.

The psychologist J. Allan Cheyne and colleagues grouped the experiences into three kinds. Knowing which one you had takes some of the terror out of it.

The demon across cultures

Long before anyone knew about REM sleep, people all over the world described the same visitor. The old English word mare named a spirit that sat on sleepers' chests, and it survives in our word nightmare. Henry Fuseli's 1781 painting The Nightmare shows exactly that: a demon crouched on a sleeping woman's chest.

• ✦Newfoundland folklore calls it being "hagged" by the Old Hag.
• ✦In Japan it is known as kanashibari, being bound as if by metal.
• ✦In Turkey the presence is called the karabasan, the dark presser.
• ✦Brazilian folklore tells of the pisadeira, a thin old woman who steps on the chests of people who sleep on a full stomach.
• ✦In parts of the Muslim world, the experience is often attributed to a jinn.

Spiritual readings of the sleep paralysis demon

Many faiths and folk traditions read sleep paralysis as a spiritual attack, and people often find comfort in prayer, a protective verse or a ritual before bed. If that is your tradition, it can genuinely help, because calm is the single best way through an episode. Others in spiritual communities see the state as a threshold between worlds, the doorway that experienced dreamers use to enter lucid dreams or out-of-body journeys.

Whatever you believe, it may help to know that the figure is overwhelmingly reported as frightening but not harmful. People wake, every time. If you read the demon symbolically, as you would read demons in dreams, it often gives a face to stress, guilt or fear that has been building in your waking life.

What triggers sleep paralysis

Episodes tend to cluster when sleep is disrupted. The most common triggers are:

• ✦Not getting enough sleep, or catching up after a short night.
• ✦An irregular schedule: shift work, jet lag, all-nighters, very late weekends.
• ✦Sleeping on your back, which many people with sleep paralysis notice.
• ✦Stress and anxiety.
• ✦Napping in the daytime, especially long naps.
• ✦Some sleep conditions, including narcolepsy, where sleep paralysis is a common feature.

How to get out of sleep paralysis

In the moment, fighting hard tends to make the fear and the pressure worse. Try this instead.

1. 1.Remind yourself what this is: sleep paralysis, harmless, and it will pass in moments.
2. 2.Breathe slowly and steadily rather than gasping. Your breathing is working, even if it feels shallow.
3. 3.Focus on moving something small: wiggle a finger or a toe, or scrunch your face. Small movements often break the paralysis.
4. 4.Close your eyes if you can, so the figure has less to work with, and let yourself drift back to sleep or wake.
5. 5.When it ends, sit up, turn on a light and let your body fully wake before lying down again.

Sleep paralysis, false awakenings and nightmares

Sleep paralysis often travels with two other experiences, and telling them apart helps. In a false awakening, you dream that you have woken in your bedroom, so the room looks right even though you are still fully dreaming; some people slide from one into the other and back. A nightmare is a frightening dream with a story, and you wake from it able to move. Sleep paralysis is the only one of the three in which you are genuinely awake and seeing your real room, unable to move. If the episode began inside a dream, that dream is worth writing down, because it often shows what was weighing on you when the paralysis struck.

Preventing episodes

Regular sleep is the most reliable prevention: the same bedtime and wake time, enough hours, and a calm wind-down. Try sleeping on your side if you notice episodes on your back. If sleep paralysis happens often, frightens you badly, or comes with sudden sleep attacks or extreme sleepiness during the day, raise it with a doctor, who can check for an underlying sleep condition.

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