Sleep paralysis causes and the demon behind it, across five countries

You wake up and cannot move. Something is sitting on your chest. In Newfoundland they had a name for her long before anyone measured brain waves: the Old Hag, a witch who climbs onto sleepers and holds them down. The word nightmare carries the same idea in its bones, from mare, the thing that presses.

Two hundred years later the visitor changed shape. In modern American accounts the figure in the room is often described as an alien, and researchers have written about that shift.

Tell us what worked for you

Somewhere out there, it is the answer someone needs.

Write a post

What is actually happening

During REM sleep the body switches off most muscle control. That is the safety catch that stops you acting out a dream. When the switch stays off a moment too long, you surface into consciousness while your body is still asleep.

The hallucinations that come with it fall into three documented groups. A sense of an intruder in the room. Pressure on the chest, the incubus type. And unusual bodily sensations, floating or falling. They can arrive together.

Waking from a supine position comes up repeatedly in the literature as the position where episodes cluster.

The same event, five different monsters

Country	Local name	How it is read	Evidence level
United States, Newfoundland	Old Hag	A witch sits on the sleeper; in modern accounts, alien abduction	Folk belief
Japan	Kanashibari	Bound in chains, attributed to a Buddhist deity's spell	Folk belief
Brazil	Pisadeira	An old woman with long nails treads on the full-bellied sleeper	Folk belief
Egypt and the Middle East	Jinn	The work of a jinn	Folk belief
South Korea	Gawi-nullim	A ghost pressing down on the body	Folk belief

In United States

The Old Hag was named and studied in Newfoundland, first in the anthropological literature of the late 1970s. She sits on the chest of a sleeping person, and the person cannot move or speak.

What makes the American case useful is what came next. The reviews note that in contemporary accounts the same paralysis, the same presence and the same pressure get told as alien abduction. The physiology held still while the story moved.

In Japan

Kanashibari means bound in chains. The name traces back to a Buddhist deity said to bind the body with a spell.

Then comes the twist worth sitting with. A 1987 study of Japanese university students reported a strikingly high prevalence of isolated sleep paralysis, and a 1998 comparison of Japanese and Canadian students pointed the same way. One reading is that having a common word for the experience makes people recognise and report it. More vocabulary, not more disease.

In Brazil

The Pisadeira waits on the roof. When someone eats a heavy meal and lies down flat, she comes down and treads on their chest with long nails. The figure originates in the southeast of the country and varies by region.

A piece of household advice sits inside the ghost story: do not eat a big meal and lie straight down.

In Egypt

In Egypt and across the Middle East the episode is read as the work of a jinn, and this region anchors the most practically useful research finding in this article.

Where the experience is interpreted supernaturally, fear and symptom severity are reported at higher levels. In an Egyptian sample, half of respondents reported a fear of dying. The interpretation you carry into the episode shapes how bad the episode is.

In South Korea

Korean has a dedicated verb for it, gawi-nullida, and the traditional reading is a ghost pressing the body down. Academic sources mention ghost-oppression folklore as the Korean counterpart.

Turkey has Karabasan. China describes ghost oppression, Thailand has Phi Am, Mexico says the dead one climbed on me, and Cambodia has a ghost that pushes you down. The list is long and the physiology behind all of it is one thing.

Latest in this topic

Woke up unable to move three times this week. Does sleeping on your back really matter that much?
PaperLantern · KR · Sleep paralysis

Lights out at 11, still awake at 2. The advice that helped was to stop lying there.
SlowRiver · JP · Can't sleep

Join the community

What actually reduces it

The triggers that recur across the literature are sleep deprivation, irregular sleep timing and sleeping on your back. All three are adjustable.

The Egyptian finding adds one more lever. Knowing what this is makes it less frightening, and less fear appears to mean less severe episodes. The paralysis lasts minutes at most and nothing dangerous happens during it.

When to see a doctor

Frequent episodes together with heavy daytime sleepiness are worth investigating, because narcolepsy needs to be ruled out. The case is stronger if you also dream immediately on falling asleep, or lose muscle strength when you laugh. A sleep clinic can sort that out.

Frequently asked

Is sleep paralysis dangerous?

Not in itself. It is REM muscle atonia carrying over into waking, and it usually resolves within minutes. Frequent episodes combined with daytime sleepiness are worth a check for other sleep disorders.

Why does it keep happening to me?

The factors that come up repeatedly are sleep deprivation, an irregular sleep schedule and sleeping supine. Adjusting those three reduces frequency for many people.

Why do people see the same figure across countries?

The three hallucination types, intruder, chest pressure and bodily distortion, are consistent. Each culture supplies its own character to explain them, which is how one physiological event produced the Old Hag, the Pisadeira and the jinn.

How do I break out of it faster?

Moving a small muscle such as a finger or toe is widely suggested, though the evidence behind it is thin. What is certain is that it ends on its own, and knowing that lowers the fear.

The Old Hag, the jinn and the demon on your chest, explained