What are Circadian Rhythm Disorders?

After a 24-hour cycle, changes in a person’s physical, behavioral and mental aspects are manifested. These changes are called circadian rhythms and they are very important in determining the sleeping pattern of a person – when does he wake up and when does he sleep during a 24-hour cycle.

The human body’s master clock is the suprachiasmatic nucleus (SCBN) which controls the production of melatonin or sleep hormone. The SCN is near the optic nerve and relays information from the eyes to the brain. The SCN basically commands the brain to make more melatonin when there is less light thus making a person sleepy.

The 24-hour phasing of a person’s brain waves, hormone production, cell generation and other pertinent biological activities are regulated by the circadian rhythms. If the circadian rhythm is disrupted, a person’s sleep-wake pattern, hormone release, body temperature and all other important bodily functions are affected. Such disruption might lead not only to insomnia but also depression, obesity, bipolar disorder and diabetes.

Causes of Circadian Rhythm Disorder

The rises and dips of a person’s circadian rhythm are set at different times each day. For most adults, the rise and dips are between 2:00 to 4:00 A.M and 1:00 to 3:00 P.M. Variations do occur as there are persons who thrive in the morning or in excellent mood and physical capacity in the evening. In a sense, a person is less likely to fall asleep during the dips if he gets the recommended sleep but more likely to fall asleep if he is sleep-deprived. On the other hand, circadian rhythm also props a person to be more energetic and alert at certain hours of each day.

Disruptions of a person’s circadian rhythm may happen due to changing time zones, shift work, pregnancy, deviations in routine, medications, mental health and/or medical problems.

Related Circadian Rhythm Disorders

Who are more exposed to circumstances that may lead to the disruption of the circadian rhythm?

Shift worker or persons who rotate work such as doctors, nurses, factory worker, call center personnel, are more likely to develop shift work syndrome.

Jetlag or rapid time zone changes syndrome indicated extreme sleepiness and loss of daytime alertness. This is especially true in people whose jobs entail them to travel from one time zone to another.

A person with Advanced Sleep Phase Syndrome (ASPD) tends to sleep and wake up earlier than most. He may sleep between 6:00 pm and 9:00 pm and then wakes up between 1:00 am and 5:00 am

Delayed Sleep Phase Syndrome or DSPS is a sleep timing disorder wherein a person who falls asleep very late at night and finds it difficult to wake up for school, work or any event.

Totally blind person may exhibit Non-24 Hour Sleep Wake Disorder. Since a blind person cannot discern light, his circadian rhythm clock is greatly affected.

If a person has an untreated sleep disorder, he may develop circadian rhythm disorder.

Do you have a sleep apnoea? If you think you have a sleep disorder, call us now for assessment. Our staff are highly trained and experienced to help you.