Circadian rhythm sleep

November 12, 2012

Circadian rhythm sleep

Circadian rhythm sleep is a disorder that causes either a constant or recurring disruption of sleep that is severe enough to cause insomnia or severe tiredness throughout the day.

An introduction to circadian rhythm sleep

The name circadian rhythm refers to the disrupted or imbalanced sleep-wake cycle. It essentially looks at the rhythms of sleep and awake that occurs within a 24 hours period. Some people may experience disrupted sleep pattern on a persistent basis, whilst others find that it is a recurring disruption. The ultimate result of circadian rhythm sleep is the impaired ability to function due to excessive tiredness or insomnia. The Diagnostic and Statistical Manual of Mental Disorders has classed circadian rhythm sleep disorder as one of a number of primary sleep disorders. Within this category it is known as a dyssomnia, a condition defined by irregularities in ones quality, timing or amount of sleep. The cause of the disturbed sleep patterns in this condition is due to a mismatch between an individuals natural, circadian system and the external demands that are placed on it.


Circadian rhythm sleep disorder can be separated into 4 types, these are known as delayed sleep, jet lag, shift work and unspecified.

  1. Delayed sleep. The primary cause of this stage of the sleep disorder is excessive demands that are placed on the natural sleep system through modern society. In many cases a psychosocial stressor or traumatic event that takes place in the individuals life that causes them psychological stress or discomfort. The results of this condition usually include chronic sleep deprivation and the habit of sleeping very late. It becomes increasingly harder to break the habit of sleeping late leading to sleeping in unsociable hours. In the delayed sleep type, the quality of sleep is not affected and once asleep they stay asleep.

  2. Jet lag. This occurs when an individual’s circadian cycle is disrupted because of travelling through time zones.

  3. Shift work. This is the mismatch of the circadian cycle and the cycle necessary for shift work. Those who have to work at night most often experience this, particularly when they attempt to switch back to a normal pattern on their days of.

  4. Unspecified. This is the term used for when circadian rhythm sleep disorder occurs but it caused by any of the three previous causes.


Treatment varies depending on the type of the disorder the patient is suffering from. In more mild cases the problem can sometimes be resolved through the individual sticking to s strict sleep schedule. In more extreme cases an incremental adjustment may be necessary, whereby the individual tries to sleep 15 minutes earlier each night. In the case of jet lag it usually sorts itself out after a day or so when the body has regulated itself to the new time zone.

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