The human sleep cycle repeats itself about every:

Question

Quizplus · Accepted Answer

The human sleep cycle repeats itself about every 90 minutes. This cycle includes both non-REM sleep and REM sleep, with each stage lasting a different amount of time. Non-REM stages make up the majority of sleep time, with stage 1 lasting a few minutes, stage 2 lasting about 20 minutes, and stage 3 lasting about 30 minutes. REM sleep usually occurs in cycles of about 90 minutes, with each REM stage generally getting longer as the night progresses.

The Human Sleep Cycle Repeats Itself About Every