REM sleep (Rapid Eye Movement sleep) is a stage of sleep that occurs cyclically throughout the night in most mammals, including humans. It is characterized by rapid eye movements, increased brain activity, and muscle paralysis.
During REM sleep, the brain is highly active and appears to be processing information from the previous day. This is why REM sleep is often associated with dreaming. Dreams during REM sleep can be vivid, emotional, and often bizarre.
In addition to its role in dreaming and memory consolidation, REM sleep is also believed to be important for overall brain health. Studies have shown that prolonged sleep deprivation and disruption of REM sleep can have negative effects on cognitive function, mood, and physical health.
REM sleep typically accounts for about 20-25% of total sleep time in adults, with each cycle of REM sleep lasting about 90-120 minutes. The amount of time spent in REM sleep can vary depending on age, with infants and young children spending more time in REM sleep than adults.
Disruptions to REM sleep can occur in a number of conditions, including sleep disorders such as obstructive sleep apnea and narcolepsy, as well as certain medications and substances. Treatment for REM sleep disorders may involve lifestyle changes, medication, or other therapies to improve the quality and duration of sleep.