How long is a typical sleep cycle?

A typical sleep cycle lasts approximately 90 minutes. This cycle consists of several stages, including both non-REM (rapid eye movement) and REM sleep. During a full night’s sleep, a person usually experiences multiple cycles—commonly around four to six—allowing for the necessary stages of sleep to promote restorative processes.

As the sleep cycles continue throughout the night, the duration of REM sleep within each cycle can increase, while deep sleep may decrease. This pattern is crucial in terms of cognitive function, emotional regulation, and physical recovery. Understanding the structure of the sleep cycle is fundamental for sleep technologists, as it aids in assessing sleep quality and diagnosing potential sleep disorders. The other durations listed do not accurately reflect the length of a full sleep cycle, thereby highlighting the importance of recognizing the 90-minute timeframe for optimal interpretations in polysomnographic studies.