9781422273890

phase lasts approximately one hour, although that varies throughout the course of the night. As the sleep cycle goes on, NREM phases become shorter and the person spends more time in the second type of sleep, REM. REM Sleep When the N3 phase of NREM sleep comes to an end, the person “ascends” back to N2 sleep, meaning the brain gradually becomes more active. This leads to REM sleep, also called “active” sleep because of that increase in brain

Being asleep is not just one state of being, but rather a series of cycles.

Teen Guides to Health & Wellness: Sleep and Hygiene

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