Circadian rhythm, or the internal body clock, is responsible for regulation of sleep patterns during a 24 hour period. Naturally, most people feel awake during the day and tired once night falls. For those with circadian rhythm disorder, this is not the case.
The primary feature of circadian rhythm disorders is the disruption of sleep patterns resulting from a malfunction in the internal body clock or a misalignment between the internal body clock and the external environment regarding the timing and duration of sleep. Individuals with Circadian Rhythm Disorders often complain of insomnia at certain times and excessive sleepiness at other times of the day.
Advanced Sleep Phase Syndrome: Individuals who are extremely tired in the early evening, but wake up early.
Delayed Sleep Phase: Individuals who are awake into the early morning hours and prefer to sleep into the late morning or early afternoon.
Non-24-Hour Sleep-Wake Syndrome: The circadian rhythm varies, shifting later each day. This is most associated with individuals whose brains receive no lighting cues, such as the blind.
The cause of a circadian rhythm disorder can be internal – disease or genetics, or external – the crossing of multiple time zones. Upon the identification of the cause of the circadian rhythm disorder your sleep specialist will assist you in developing an effective treatment plan.