Deep sleep, also known as slow-wave sleep or Stage 3 NREM (non-rapid eye movement) sleep, is a stage of sleep characterized by slow brain waves, relaxed muscles, and difficult arousal. It plays a crucial role in restoring physical energy and promoting overall well-being.
This term refers to rapid eye movement sleep, which is a stage of sleep associated with vivid dreaming, muscle paralysis, and increased brain activity.
Narcolepsy is a neurological disorder that causes excessive daytime drowsiness and sudden bouts of uncontrollable sleep attacks. It disrupts normal sleep-wake cycles, including the ability to maintain deep sleep stages.