Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Sleep paralysis is a temporary inability to move or speak that occurs when transitioning between sleep and wakefulness. It often accompanies vivid hallucinations and a feeling of pressure on the chest.
Related terms
Hypnagogic Hallucinations: These are vivid sensory experiences that occur during the transition from wakefulness to sleep, often accompanying sleep paralysis.
Rapid Eye Movement (REM) Sleep: REM sleep is a stage of sleep characterized by rapid eye movements, increased brain activity, and dreaming. Sleep paralysis tends to happen during REM sleep.
Nightmare Disorder: This refers to recurrent nightmares that cause significant distress or impairment in daily functioning. Sleep paralysis can be associated with intense nightmares.