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Sleep and Circadian Rhythm Disorders

Circadian rhythm disorders are disruptions in a person's circadian rhythm -- a name given to the "internal body clock" that regulates the (approximately) 24-hour cycle of biological processes. The term circadian comes from Latin words that literally mean around the day. There are patterns of brain wave activity, hormone production, cell regeneration, and other biological activities linked to this 24-hour cycle.

The circadian rhythm is important in determining sleeping patterns such as when we sleep and when we wake, every 24 hours.The normal circadian clock is set by the light-dark cycle over 24 hours.

Recommended Related to Sleep Disorders

Scared to Sleep

Every night, for the last 10 years, Traci Coulter has struggled to sleep. Minutes tick by, then hours. Coulter begins to fret about her to-do list the next day and all her responsibilities as a public relations executive. To make matters worse, she knows a garbage truck is coming by at 3 a.m. and will wake her up - a thought that only makes her more anxious. “It’s an ongoing cycle of not getting the rest that I need, and it causes such anxiety for me,” says Coulter, 38, who lives in New York City...

Read the Scared to Sleep article > >

 

What Causes Circadian Rhythm Disorders?

Circadian rhythm disorders can be caused by many factors, including:

  • Shift work
  • Pregnancy
  • Time zone changes
  • Medications
  • Changes in routine such as staying up late or sleeping in

 

Common Circadian Rhythm Disorders

  • Jet Lag or Rapid Time Zone Change Syndrome: This syndrome consists of symptoms that include excessive sleepiness and a lack of daytime alertness in people who travel across time zones.
  • Shift Work Sleep Disorder: This sleep disorder affects people who frequently rotate shifts or work at night.
  • Delayed Sleep Phase Syndrome (DSPS): This is a disorder of sleep timing. People with DSPS tend to fall asleep very late at night and have difficulty waking up in time for work, school, or social engagements.
  • Advanced Sleep Phase Syndrome (ASPD): This is a disorder in which a person goes to sleep earlier and wakes earlier than desired. ASPD results in symptoms of evening sleepiness, going to bed earlier (for example, between 6 p.m. and 9 p.m.), and waking up earlier than desired (for example, between 1 a.m. and 5 a.m.)
  • Non 24-Hour Sleep Wake Disorder:  This disorder frequently affects those that are totally blind since the circadian clock is set by light-dark cycle over a 24 hour period. In non-24 hour sleep wake disorder the cycle is disturbed. The disorder result in drastically reduced sleep time and sleep quality at night and problems with sleepiness during daylight hours.

 

How Are Circadian Rhythm Disorders Treated?

Circadian rhythm disorders are treated based on the kind of disorder diagnosed. The goal of treatment is to fit a person's sleep pattern into a schedule that allows him or her to meet the demands of their lifestyle. Therapy usually combines proper sleep hygiene techniques and external stimulus therapy, such as bright light therapy or chronotherapy. Chronotherapy is a behavioral technique in which the bedtime is gradually and systematically adjusted until a desired bedtime is achieved. Bright light therapy is designed to reset a persons circadian rhythm to a desired pattern. When combined, these therapies may produce significant results in people with circadian rhythm disorders.

 

WebMD Medical Reference

Reviewed by Louis R. Chanin, MD on July 27, 2012
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Is This Normal? Get the Facts Fast!

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You say you are able to function well with fewer than seven hours of sleep. Some people say they can function on four to six hours of sleep each night, but research shows that adults who get fewer than seven hours of sleep — whether for just one night or over the course of days, weeks, or months — have more difficulty concentrating and more mood problems than people who sleep seven to nine hours.

Since you usually get too little sleep, please talk to your doctor about your sleep patterns. Poor quality sleep can affect many areas of your life and health, and your doctor may be able to help you if you have insomnia or other conditions affecting your sleep.

Sleep deprivation can have both short- and long-term consequences. Learn more about the health consequences of sleep loss. If you're concerned about having trouble falling asleep or staying asleep, assess your risk for a sleep disorder.

It's not surprising you feel that you're not functioning at your best today. Some people say they can function on four to six hours of sleep each night, but research shows that adults who get fewer than seven hours of sleep — whether for just one night or over the course of days, weeks, or months — have more difficulty concentrating and more mood problems than people who sleep seven to nine hours.

Since you usually get too little sleep, please talk to your doctor about your sleep patterns. Poor quality sleep can affect many areas of your life and health, and your doctor may be able to help you if you have difficulty sleeping, have insomnia, or have other sleep disorders.

Learn more about the health consequences of sleep loss. If you're concerned about having trouble falling asleep or staying asleep, assess your risk for a sleep disorder.

It's not surprising you feel that you're not functioning at your best today. Some people say they can function on four to six hours of sleep each night, but research shows that adults who get fewer than seven hours of sleep — whether for just one night or over the course of days, weeks, or months — have more difficulty concentrating and more mood problems than people who sleep seven to nine hours.

It's good that you usually do get more sleep, since sleep deprivation can have both short- and long-term consequences. Learn more about the health consequences of sleep loss. And if you're concerned about having trouble falling asleep or staying asleep, assess your risk for a sleep disorder.

You say you are able to function well with fewer than seven hours of sleep. Some people say they can function on four to six hours of sleep each night, but research shows that adults who get fewer than seven hours of sleep — whether for just one night or over the course of days, weeks, or months — have more difficulty concentrating and more mood problems than people who sleep seven to nine hours.

It's good that you usually do get more sleep because sleep deprivation can have both short- and long-term consequences. Learn more about the health consequences of sleep loss. And if you're concerned about having trouble falling asleep or staying asleep, assess your risk for a sleep disorder.

It's not surprising you feel that you're not functioning at your best today. Some people say they can function on four to six hours of sleep each night, but research shows that adults who get fewer than seven hours of sleep — whether for just one night or over the course of days, weeks, or months — have more difficulty concentrating and more mood problems than people who sleep seven to nine hours.

Since you usually get less sleep, please talk to your doctor about your sleep patterns. Poor quality sleep can affect many areas of your life and health, and your doctor may be able to help you if you have difficulty sleeping or have insomnia or other sleep disorders.

Learn more about the health consequences of sleep loss. If you're concerned about having trouble falling asleep or staying asleep, assess your risk for a sleep disorder.

It's wonderful that you got a good night's sleep last night. Many people struggle to do so. Having a good sleep routine often is the key to getting the quality sleep night after night that your body needs for optimal health. Whether your sleep routine involves taking a warm bath, reading a book, or meditating, it's important to keep your bedtime and routine consistent every night and wake up around the same time every morning.

Click here to read more about the importance of sleep. If you're concerned about having trouble falling asleep, staying asleep, or sleeping too much, assess your risk for a sleep disorder.

It's unfortunate you're not functioning at your best today. You say you had a good quantity of sleep last night, but maybe the quality of your sleep is not as good as it could be? Having a good sleep routine — including a consistent bedtime and wake time — often is the key to getting the quality sleep night after night that your body needs for optimal health. Since you usually sleep this amount, if you often aren't feeling your best, you should consider talking to your doctor. Could you have an underlying condition? Are you feeling anxious or depressed? Have you taken medication that disrupted your sleep? Do you or could you have sleep apnea? Or do you naturally require a little bit more sleep?

Although sleep is crucial for optimal health, some research suggests that sleeping too much can also have negative consequences. Learn more about sleep. If you're concerned about having trouble falling asleep, staying asleep, or sleeping too much, assess your risk for a sleep disorder.

It's unfortunate you're not functioning at your best today. You say you had a good quantity of sleep last night, but maybe the quality of your sleep is not as good as it could be? Having a good sleep routine — including a consistent bedtime and wake time — often is the key to getting the quality sleep night after night that your body needs for optimal health. Since you usually sleep longer, if you often aren't feeling your best, you should consider talking to your doctor. Could you have an underlying condition? Are you feeling anxious or depressed? Have you taken medication that disrupted your sleep? Do you or could you have sleep apnea? Or do you naturally require a little bit more sleep?

Although sleep is crucial for optimal health, some research suggests that sleeping too much can also have negative consequences. Learn more about sleep. If you're concerned about having trouble falling asleep, staying asleep, or sleeping too much, assess your risk for a sleep disorder.

It's wonderful that you got a good night's sleep last night. Many people struggle to do so. Having a good sleep routine often is the key to getting the quality sleep night after night that your body needs for optimal health. Whether your sleep routine involves taking a warm bath, reading a book, or meditating, it's also important to keep bedtime consistent and wake up around the same time every morning.

Although sleep is crucial for optimal health, some research suggests that sleeping too much can have negative consequences. Learn more about sleep. If you're concerned about having trouble falling asleep, staying asleep, or sleeping too much, assess your risk for a sleep disorder.

It's unfortunate you're not functioning at your best today. You say you had a good quantity of sleep last night, but maybe the quality of your sleep is not as good as it could be? Having a good sleep routine — including a consistent bedtime and waking up at the same time — often is the key to getting the quality sleep night after night that your body needs for optimal health.

Since you usually get less sleep, please talk to your doctor about your sleep patterns. Poor quality sleep can affect many areas of your life and health, and your doctor may be able to help you if you have insomnia, another sleep disorder, or conditions affecting your sleep.

Learn more about the health consequences of sleep loss. If you're concerned about having trouble falling asleep or staying asleep, assess your risk for a sleep disorder.

It's wonderful that you got a good night's sleep last night. Many people struggle to do so. Having a good sleep routine often is the key to getting the quality sleep night after night that your body needs for optimal health.

Since you usually get less sleep, talk to your doctor about your sleep patterns. Poor quality sleep can affect many areas of your life and health, and your doctor may be able to help you if you have insomnia or another sleep disorder or conditions affecting your sleep.

Learn more about the health consequences of sleep loss. If you're concerned about having trouble falling asleep or staying asleep, assess your risk for a sleep disorder.

SOURCES:

Centers for Disease Control and Prevention (CDC). Effect of short sleep duration on daily activities--United States, 2005-2008. MMWR Morb Mortal Wkly Rep 2011; 60:239.

Carskadon, MA, Dement, WC. Normal Human Sleep: An Overview. In: Principles and Practices of Sleep Medicine, Fifth, Kryger, MH, Roth, et al. (Eds), Elsevier Saunders, St. Louis, MO 2011. p.16.

Harvard University: "Sleep, Performance, and Public Safety."

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