Sleeplessness and Circadian Rhythm Disorder Topic Guide

Sleeplessness and Circadian Rhythm Disorder Sleeplessness and Circadian Rhythm Disorder: A person's circadian rhythm is an internal biological clock that regulates a variety of biological processes according to an approximate 24-hour period. A disorder of the circadian rhythm may cause sleeplessness on at transient or chronic basis. The disorder can be caused by:
  • air travel across time zones,
  • shift work,
  • irregular sleep-wake cycle,
  • delayed sleep phase syndrome, and
  • advanced sleep-phase syndrome.


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