At night we’d like to sleep peacefully and restore energy. Nevertheless, it is difficult to find a person who has never encountered some strange and unpleasant sensations accompanying sleep.
Viral Inspiral decided to tell you about such experiences, which remain a mystery for science to this day.
Sleep paralysis

How it feels: The person wakes up at night and cannot move. Added to this are frightening hallucinations and a feeling that there is someone else in the room. In antiquity, this state was associated with mischiefs of evil spirits.
Why it happens: Normally, when we fall asleep, we are paralyzed so that we don’t sleepwalk and such. With sleep paralysis, our muscles “turn off” when the brain is awake.
Approximately 7% of the population have experienced sleep paralysis at least once (source). They say this is more likely when sleeping on the back.