Sleep paralysis

Sleep paralysis is a temporary inability to move or speak while falling asleep or waking, caused by REM-sleep muscle paralysis persisting into conscious awareness.

Rapid eye movement sleep: A sleep stage marked by vivid dreaming, rapid eye movements, and temporary suppression of most skeletal-muscle activity. Sleep paralysis occurs when REM muscle suppression continues into wakefulness.
Narcolepsy: A chronic neurological disorder that disrupts sleep-wake regulation and can cause excessive daytime sleepiness. Recurrent sleep paralysis can accompany narcolepsy, though it also occurs without it.
Nightmare: A disturbing dream that causes strong negative emotions and may prompt awakening. A nightmare occurs within a dream, while sleep paralysis involves awareness with movement temporarily blocked.
Old Hag: A folklore figure believed to sit on a sleeping person’s chest and prevent movement or breathing. The figure gives a traditional supernatural explanation for a common sleep-paralysis sensation.
Atonia: A temporary loss of muscle tone that prevents most voluntary movement. REM atonia is the paralysis that remains during a sleep-paralysis episode.
Obstructive sleep apnea: A disorder in which repeated upper-airway obstruction interrupts breathing during sleep. Sleep disruption from apnea may be associated with episodes of sleep paralysis.
Night terror: An episode of intense fear and arousal arising from deep non-REM sleep, often with limited awareness afterward. Night terrors arise from a different sleep stage and usually involve marked physical arousal.
Incubus: A male demon in European folklore believed to attack people during sleep. Incubus stories have been linked to reports of a sensed presence and chest pressure.
Hypnagogia: The transitional state between wakefulness and sleep, sometimes accompanied by vivid sensory experiences. Episodes at sleep onset can combine partial awareness with dreamlike sensations.
Sleep hygiene: Habits and environmental practices that support regular, restorative sleep. Regular sleep schedules and adequate sleep can reduce common episode triggers.

Linked from 13 pages