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.
Sleeplessness and Circadian Rhythm Disorder:
Sleep Disorders and Aging Sleep problems are common among people as they age. People tend to sleep less in later years, but other sleep issues can be caused by a variety of medical symptoms and drug side effects. Daytime sleepiness and fatigue and reduce the quality of life for senior citizens. Medications and sleep hygeine, or a combination of the two, can help.