You are reading What Happens When the Body’s Circadian Rhythm is Altered?


What Happens When the Body’s Circadian Rhythm is Altered?

January 1, 2018


Not being able to fall asleep, feeling tired, and having difficulty concentrating are all common symptoms of jet lag disorder. This syndrome generally affects individuals who cross different time zones and it may take a few days for the body to adjust back to normal. A night’s rest is affected by this change in habit before an individual has a chance to adapt to the new rhythm. This occurs because the circadian rhythm, the internal biological clock that regulates different bodily functions, is altered. Jet-leg disorder is one of the circadian rhythm disorders. Others include delayed sleep phase syndrome and advanced sleep phase syndrome – explains Dr. Lara Fratticci, neurologist at Humanitas.


In order for there to be no circadian rhythm disturbances, our biological clock must proceed in harmony with the changing day and night hours: “The circadian rhythm oversees the temporal distribution of wakefulness and sleep. It interacts with the homeostatic process of the body and signals how many hours of sleep are necessary, according to previous experienced wakefulness. The circadian rhythm is a sort of pacemaker that is found in the hypothalamus – explains Dr. Fratticci – more specifically, in the suprachiasmatic nucleus of the hypothalamus.”


Apart from regulating sleep, the circadian rhythm regulates other biological functions such as hormone production and metabolism. It is affected by both external factors and internal factors: “For example, it is affected by light stimulation or melatonin levels in the blood. When there is a lack of synchronization in rhythm, with respect to the alternation between day and night, then the sleep/wake cycle is altered. In such cases, insomnia, difficulty concentrating, and irritability arise.” Here are two of the most common circadian rhythm disorders:

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Delayed sleep phase disorder

An individual with this disorder has difficulty falling asleep: “Sleeping is therefore delayed in comparison to conventional patterns of sleep and wakefulness. The individual falls asleep with great difficulty between the hours of 3:00am-6:00am and wakes up between the hours of 12:00pm-15:00pm. Moreover, if the individual needs to get up at a reasonable time to study or to go to work, he or she will suffer from sleep deprivation and their cognitive performance will be affected.”


Individuals of younger ages are more commonly affected by this disorder: “It is common in adolescence because of hormonal issues, but also because of lifestyle choices that may postpone bedtime, such as abusing alcohol or drugs.”



Advanced sleep phase disorder

This disorder is the exact opposite of the previous one: “Drowsiness occurs in the early evening hours, even after 6:00pm, and the individual tends to wake up around 1:00am to 3:00am in the morning. It is a disorder that commonly affects the elderly.”


How can you regulate your sleep/wake cycle? “After conducting a clinical assessment, it has been defined that lifestyle changes should be made accordingly or advantage should be taken of natural elements for synchronizing the biological clock with alternations of light and darkness. These elements include exposure to sunlight during the waking hours or the intake of melatonin in the evening hours. Your doctor may also prescribe short half-life hypno-inductive medications so that your work or school performance is not affected” concludes Dr. Fratticci.


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