The circadian system, also called the biological clock, is the natural daily cycle that regulates patterns of rest and activity. Circadian rhythm helps people maintain regular sleeping and waking schedules, ensuring that body systems and the brain get the proper amount of rest each night. There are many different types of circadian rhythm disorders that can disrupt the cycle and lead to sleeplessness, drowsiness during waking hours, and general ill feelings. A circadian rhythm disorder may be temporary, as is the case with jet lag or working unusual hours, or it may be a chronic problem that affects a person for months or years at a time.
In most cases, a circadian rhythm disorder is short-lived and brought about by traveling to different time zones, an illness, or changing shifts at a job. A person may be to get enough sleep when the timing of his or her daily routine is altered. Disorders are especially common among people who take on late-night or overnight shifts after long being accustomed to daytime work. It is often difficult for people to make themselves sleep when they are used to being awake, especially if it is light outside.
A chronic circadian rhythm disorder is a clinically diagnosable condition that is related to a brain abnormality or chemical imbalance. The most common types are advanced sleep-phase syndrome (ASPS) and delayed sleep-phase syndrome (DSPS). ASPS involves an inability to stay awake through the early evening hours and a chronic tendency to wake up very early in the morning, despite efforts to change sleep patterns. DSPS sufferers usually cannot get into a regular sleep pattern at all.
Treatment for a circadian rhythm disorder depends on the types of problems a patient faces and the amount of time he or she has been struggling with sleeplessness. Most mild cases related to travel or work hours go away within a few days once the body becomes accustomed to a new pattern of sleeping and waking. If a normal pattern cannot be established or a person is diagnosed with a chronic disorder, he or she can take steps to relieve symptoms. Maintaining a healthy diet, getting regular exercise, and taking steps to reduce stress can all help to increase alertness during waking hours and relieve insomnia at bedtime.
Some people who suffer from chronic circadian rhythm problems benefit from behavioral therapy sessions with psychologists. A therapist can help a client identify environmental causes stress and anxiety and learn how to better deal with them. Medications may be considered if other treatment measures fail and a person's health begins to decline. Prescription sleep agents such as melatonin and anxiety drugs such as benzodiazepines are usually effective at managing a circadian rhythm disorder.