Scientific explanations for sleep paralysis and hypnagogic jerks

Common nocturnal phenomena such as the sensation of falling and sleep paralysis have scientific explanations rooted in sleep cycles.

Hypnagogic jerks, or sleep myoclonus, occur during the transition between wakefulness and sleep. As the body relaxes and heart rate slows, the brain may misinterpret excessive relaxation as a sign of falling, triggering muscle spasms that cause a sudden awakening. While benign, these episodes can be triggered by stress, anxiety, fatigue, or excessive stimulant consumption.

Sleep paralysis occurs during the REM (Rapid Eye Movement) phase, where the brain is highly active but the body is temporarily immobilized to prevent physical enactment of dreams. If consciousness returns before this immobility fades, individuals may feel unable to move or speak. Factors such as stress, irregular schedules, and poor sleep hygiene can increase the frequency of these episodes.