Circadian Rhythm Disorder
Overview of Circadian Rhythm DisordersCircadian means “about 24 hours”, referring to the usual day/night cycle. Circadian rhythms are those processes with a 24 hour cycle. As with most animals, humans have circadian rhythms. The most obvious is the cycle of sleep and wakefulness. There is a sliding scale of when people prefer to go to bed and when they naturally wake up. People at either end of the scale often suffer because there are typically social or work boundaries around 'normal' life – i.e., socializing and family life often revolves around the early evening and work typically requires that we get up sometime before 8am. Symptoms of Circadian Rhythm DisordersPeople who find themselves excessively tired in the early evening, but wake early are referred to as having advanced sleep phase syndrome. The opposite, where people stay up into the early hours of the morning and would prefer to sleep in, is referred to as delayed sleep phase syndrome. Other types of circadian rhythm disorders exist such as non-24-hour sleep-wake syndrome where the need for sleep changes every day, typically moving an hour or two forward every day. This is seen more commonly in blind people who cannot use the rising and setting of the sun to reset their body-clocks as sighted people do. Causes of Circadian Rhythm DisordersThe cause of a circadian rhythm disorder can be internal – a fact of our genetic makeup or the result of another disease or disorder – or external, for example jet lag, where we travel across time zones quicker than our body can adapt. Shift work, where someone must try to work when the body craves sleep and sleep when they are alert, is another relatively common rhythm disorder, referred to as shift work sleep disorder. For more information on specific sleep disorders, see their pages in this section of the website. Talk to your doctor or sleep specialist if you believe you may have a circadian rhythm disorder. |
