Sleep disorders: Circadian rhythm sleep disorders

What is a circadian rhythm sleep disorder?
Your circadian rhythm is your internal clock that influences, among other things, the daily cycle of waking and sleeping. The sleep-wake cycle is usually in line with the external cycle of light and dark. If you have a circadian rhythm sleep disorder, you do not wake and sleep at the "normal" times. Your natural body clock is out of synch.

What causes circadian rhythm sleep disorder?
A circadian rhythm sleep disorder might be caused by external forces - like the jet lag that results from travelling to a different time zone or the disrupted sleep patterns common to those who work the night shift or irregular split shifts. Internal forces can also cause a circadian rhythm sleep disorder, as in the case of people who are natural "larks" (early birds) or night owls.

What are some types of circadian rhythm sleep disorders?

• Jet lag occurs when you travel quickly across more than two time zones.
• Shift work disorder, as the name implies, occurs when people work evening and night shift and is more common when the shift times change rather that stay constant.
• Advanced sleep phase syndrome occurs when your body clock tells you to sleep and wake up earlier than normal (e.g., falling asleep in the early evening and waking up very early in the morning).
• Delayed sleep phase syndrome is associated with a very late bedtime of 3 am to 6 am and waking after noon.
• Non-24-hour sleep-wake syndrome occur when sleep time shifts by 1 to 2 hours daily.

What are the symptoms of circadian rhythm sleep disorders?

The symptoms of circadian sleep disorders include:

• sleepiness during the day
• difficulty falling asleep
• poor concentration and performance during the day

If you think you might have a circadian rhythm sleep disorder, talk to your doctor so you can receive a thorough evaluation and treatment plan.