Wachphase

Wachphase is a term used in sleep science and chronobiology to denote the period of wakefulness within the circadian cycle. The concept is most common in German-language literature and serves to distinguish active, alert time from the sleep phases NREM and REM. In humans, the Wachphase is typically the daytime interval during which individuals are awake and performing most activities, though it can be interrupted by naps or fragmented wake periods. Wakefulness is generated and sustained by brain networks including the ascending arousal system and orexin neurons, and is regulated by interactions between circadian signals and homeostatic sleep pressure.

Wachphase can be measured with actigraphy, which tracks movement, and with polysomnography or electroencephalography to classify alertness. Sleep diaries and experience sampling provide subjective estimates of wake periods. The duration and timing of the Wachphase vary with age, work schedule, light exposure, and individual chronotype, yielding diurnal or nocturnal patterns across species.

Disruptions to the Wachphase, such as misalignment of the circadian clock or shift work, are associated with sleep disorders and daytime impairment. Management approaches emphasize regular sleep-wake scheduling, controlled light exposure, and behavioral strategies, with pharmacological options used in clinical settings when appropriate.