What is the sleep cycle?

The sleep cycle refers to the progression through different stages of sleep that typically occurs multiple times during a night. It includes non-REM (Rapid Eye Movement) sleep, which is further divided into stages 1, 2, and 3, followed by REM sleep. Each complete cycle lasts about 90 to 120 minutes and repeats approximately four to six times per night. These cycles are essential for restorative sleep, impacting memory, mood, and overall health.