Sleep paralysis is when you are conscious of your sleep, but not able to move. It occurs when a person passes between periods of wakefulness and sleep. There are two kinds of sleep paralysis, which include hypnopompic or postdormital sleep, which arises when you are about to wake up, and this is the more common form of sleep paralysis. The other kind is called hypnagogic or predormital sleep, which happens before you sleep.
During an episode of sleep paralysis, one may hallucinate, which often results in confusion, fear, restlessness, and extreme panic. This condition may also be prompted by sleep deprivation, emotional stress, or irregular sleep cycles. It is also a sign that your body is not transitioning smoothly through the stages of sleep.