This document discusses sleep paralysis, which occurs when a person wakes up but is temporarily unable to move or speak. It describes how during REM sleep, neurotransmitters normally prevent movement so people do not act out their dreams. In cases of sleep paralysis, this paralysis does not fully lift upon waking. The document notes sleep paralysis can cause hallucinations and feelings of terror. It is often associated with conditions like narcolepsy. Treatments discussed include medications, muscle relaxation, and establishing a regular sleep pattern.