Sleep Paralysis Definition
A frightening form of paralysis that occurs when a person suddenly finds himself or herself unable to move for a few minutes, most often upon falling asleep or waking up. Sleep paralysis is due to an irregularity in passing between the stages of sleep and wakefulness.
The symptoms of sleep paralysis include sensations of noises, smells, levitation, paralysis, terror, and images of frightening intruders. Once considered very rare, up to half of all people are now believed to experience sleep paralysis sometime during their life. Sleep paralysis is not considered to be a sign of a serious condition, although it can be frightening.