Sleep paralysis is caused by a disruption in the normal transition between sleep stages, particularly when rapid eye movement (REM) sleep overlaps with wakefulness. During REM sleep, the brain is active and vivid dreams occur, but the body experiences temporary muscle paralysis to prevent acting out dreams. Sleep paralysis happens when a person wakes up before this paralysis has ended, leaving the brain awake but the body unable to move
. Several factors can contribute to the occurrence of sleep paralysis:
- Sleep deprivation or irregular sleep schedules , such as shift work or jet lag, which disrupt normal sleep patterns
- Stress and anxiety , which can disturb sleep and increase the risk of episodes
- Sleep disorders like narcolepsy, insomnia, or nighttime leg cramps
- Sleeping position , especially sleeping on the back, which is associated with more frequent episodes
- Mental health conditions such as PTSD, bipolar disorder, general anxiety disorder, and panic disorder
- Family history and genetic predisposition , suggesting some people are more susceptible
- Use of certain medications (e.g., for ADHD) and substances like alcohol, which may affect sleep cycles
During an episode, people may experience hallucinations, a feeling of pressure on the chest, intense fear, and a sensation of being unable to move or speak
. In summary, sleep paralysis occurs when REM sleep muscle atonia persists into wakefulness, often triggered or worsened by sleep deprivation, irregular sleep patterns, stress, certain sleep disorders, and genetic factors
