Pathophysiology, Associations, and Consequences of Circadian Rhythm Sleep Disorder

Circadian rhythm sleep disorders (CRSDs) are a family of sleep disorders that result from a mismatch between the body's endogenous clock and the 24-h environmental and sleep-wake schedule. CRSDs are associated with significant psychological, physiological, and social consequences, ranging from minor social impact to serious medical conditions such as cardiovascular disease and neurological disorder. The degree to which a CRSD affects the individual depends greatly on the level of malsynchronization of the circadian system with requirements and schedules of daily living. This article discusses the pathophysiology, associations, and consequences of the six major CRSDs currently recognized in the International Classification of Sleep Disorders.