why does sleep paralysis happen

Sleep paralysis happens when the brain wakes up from REM (rapid eye movement) sleep but the body remains in a state of muscle paralysis typical of REM sleep. This causes a temporary inability to move or speak while being conscious. It occurs due to a disturbed REM sleep cycle where the overlap of REM sleep and waking states leads to awareness without motor control. Several factors increase the risk of sleep paralysis, including inadequate sleep, irregular sleep schedules, sleeping on the back, stress, anxiety disorders, PTSD, narcolepsy, and certain medications or substance use. Researchers also note a possible genetic predisposition. During REM sleep, the brain normally paralyzes muscles to prevent acting out dreams, but in sleep paralysis, this muscle atonia persists while consciousness returns. Sometimes, hallucinations accompany the experience, likely linked to brain activity during this state. In summary, sleep paralysis is caused by a disruption in the transition between sleep stages, particularly between REM sleep and wakefulness, making the mind awake but the body temporarily unable to move.