
Sleep Cycles: One rapid eye movement (REM) stage and three non-REM stages that altogether last about 90 to 120 minutes
Benefits: Physical and mental recuperation and memory consolidation
Disorders: Insomnia, narcolepsy, sleep apnea, night terrors, restless leg syndrome
By some estimates, the average person spends about one-third of their lives sleeping (or trying to sleep). Sleep is a resting state for the brain and body that occurs at regular intervals, and getting enough sleep is essential for maintaining good health.