Waking up and being unable to move for a few moments: the body is still in the dreaming stage.
During REM sleep, the stage in which most dreaming happens, the body's muscles relax until they cannot move: this is called atonia, and it stops you acting out your dreams. Sometimes this stillness carries on for a few seconds after the mind has woken, or sets in before it has fallen asleep. You are conscious, your eyes open, but the body does not respond. It is often frightening; it is usually harmless and passes on its own within seconds or, at most, a few minutes.
What it feels like and why
The main sign is simple: you are awake but cannot move or speak. Other sensations often join in, because the dream has not fully switched off and blends with the real room. Many people sense a presence beside the bed, a weight on the chest or difficulty breathing; others feel they are floating, spinning or leaving the body.
The sense of suffocating is frightening, but breathing carries on by itself: the diaphragm, the muscle that does the breathing, does not stop during REM sleep. Sleep paralysis is more common than people think, and it becomes more likely when you are short of sleep, keep irregular hours, work night shifts or have just crossed time zones, during stressful periods and, for many people, when sleeping on their back.
How cultures have read it
Almost every culture has given this experience a face. In Abruzzo, in central Italy, people tell of the pandafeche, a figure that sits on the sleeper's chest; in Japan it is called kanashibari, "bound as if by metal"; in Newfoundland, the Old Hag. Henry Fuseli's painting The Nightmare, from 1781, shows a demon crouched on the chest of a sleeping woman, and the English word "nightmare" itself comes from the "mare", a spirit believed to sit on sleepers' chests.
Some spiritual traditions read it as a threshold: those who watch it calmly instead of fighting it say it sometimes turns into an out-of-body experience. Medicine sees the presences and the floating as fragments of dreaming that spill into waking. The two readings look at the same moment from different angles.
Frequently asked questions
Is sleep paralysis dangerous?
Usually not: it is unpleasant, sometimes frightening, but it passes on its own and does the body no harm. It is worth talking to your doctor if it happens often, if it worries you so much that you dread going to bed, or if it comes with heavy daytime sleepiness or sudden muscle weakness when you laugh or feel strong emotion: these can be signs of a sleep disorder, such as narcolepsy, that can be recognised and treated.
What should you do during sleep paralysis?
Remind yourself that it is temporary and that your breathing carries on by itself. Rather than struggling with your whole body, focus on slow breathing and try to move something small: a finger, your toes, your eyes or the muscles of your face. A small movement is often enough to break the stillness. If images or presences appear, knowing they are part of the experience helps keep fear at bay.
How can you stop sleep paralysis from happening?
The most effective step is getting enough sleep at regular times, since lack of sleep and irregular hours make it more likely. Reducing stress and cutting back on alcohol and caffeine in the evening also help. If it mostly happens when you sleep on your back, try falling asleep on your side. If episodes stay frequent despite these changes, your doctor can help you find out why.
Keep a dream journal
Writing your dreams down as soon as you wake is the first step to remembering and recognising them. In the SideraMea journal each dream stays next to the sky of that night.