For many people jet-lag due to intercontinental trips is a common thing. And for the high profile executives and professionals such things are unavoidable. But owing to such untimely body activities, the biological clock in the human body gets disturbed and causes problems or disorders. Circadian Rhythm is a response to the light and dark conditions in living organisms. It affects the mental, physical and behavioral cycles of the body which follows a 24 hour cycle based on day and night. The study of Circadian rhythms is called chronobiology. But Circadian rhythm should not be confused with the biological clock.
A circadian rhythm is a physiological cycle of 24 hours prevalent in animals, plants, fungi, cyanobacteria and all living beings. Scientists believe that circadian rhythm are generated endogenously and offer the scope of modulation by certain external factors like temperature and sunlight. These rhythms play a key role in determining the feeding and more importantly the sleeping patterns in animals and human beings. Circadian rhythm show clear behavior of brain wave activity cell regeneration, hormone production and other cycles that are part of the daily biological cycle. Circadian word has been lifted from the Latin word circa Diem which means about a day.
The base of human brain comprise of hypothalamus that looks like a pinhead type structure is size. In this hypothalamus is present the suprachiasmatic nucleus that is in control of biological clock and supervises wake and sleep cycle of the body. This process is conducted with the help of retina which passes on information about light to the hypothalamus via nerves. By measuring the exposure to light constantly it adjusts the whole wake and sleep biological cycle.
So as to prove the fact that circadian rhythm is not only a response towards the external stimuli such as alarm clock, day light or watches but is more connected to internal biological activity, an experiment was organized by two German scientists. During this experiment these scientists locked the volunteers in a bunker so that they should live in a place which was away from light. The volunteers were allowed to remain in the bunker for around one month without letting them no about the time changes and whether it was day or night. They were encouraged to sleep whenever they felt like and carried out their activities on their own. After one month, the results revealed that the natural biological cycle in these volunteer was settled beyond 24 hours and was now 25 hours of which one third time was dedicated to sleep. Recent studies have also revealed that humans have circadian rhythm near to 24 hours.
Most of the disorders are due to disruption in the pattern of sleep. This disturbance in sleep can be owing to malfunctioning of internal body clock or disparity in between internal body clock and the outer surrounding in relevance to timing and sleep duration. Due to this disparity people affected have problem of insomnia or excess of sleepiness that affects the work at office or in studies in school leading to less efficiency. Some of the common disorders associated with circadian rhythm are: delayed sleep phase disorder, advanced sleep phase disorder, jet lag, shift work disorder and narcolepsy.
Different treatments for circadian rhythm disorders are recommended by the doctors mostly based on the intensity and type of disorder and its effect on the quality life of a person. The results are better and rapid when the treatment is individualized and hence such treatments are usually favored. Some of the treatment options for circadian rhythm problems are: