You might be having sleep paralysis. They say it's a hereditary disorder in which one experiences very frightening seconds or minutes of total body paralysis with little respiration and eye movements. It seems to have a significant relationship with anxiety. Anxiety is a neurocognitive event closely related to both psychological and physical processes, the extreme anxiety or panic may cause the release of several different signal molecules that trigger all kinds of physical events. A person experiencing Sleep Paralysis feels mortal fear or extreme panic, and hence, the brain generates and releases internal visual or auditory stimuli, producing hallucinations.