Practice of Sleep Medicine | 2021
Circadian Rhythm Sleep–Wake Disorders
Abstract
This group of diseases is characterized by a lack of synchronization of the intrinsic circadian rhythms with the light–dark alternation. Either the intrinsic pacemaker itself is disturbed or the sleep–wake rhythm deviates from a normal intrinsic circadian rhythm because of external factors. Insomnia or hypersomnia complaints, or both, are the consequence. If the patient is able to adapt the sleep times to the inner rhythm, sleep duration and quality as well as the performance in the wakeful phase are normal. Sleep disorders occur most frequently in shift workers, with negative effects on health and impaired performance at work. Sleep diaries are the basis for diagnosis, and the strict observation of defined bedtimes in combination with light therapy are the basis for therapy.