Circadian Rhythm

What is Circadian Rhythm Sleep Disorder?

The circadian rhythm is the body’s internal clock. It’s a cycle that lasts 24 hours and keeps biological processes in sync, including hormone production and cell regrowth. Your Circadian rhythm also plays a role in when you sleep. A circadian rhythm sleep disorder occurs when this internal clock is not functioning properly.


There are six main types of circadian rhythm sleep disorders. These classifications are based on when a person typically falls asleep.

  • Jet lag, or rapid time zone change syndrome: Symptoms of this type include too much sleepiness and lack of daytime alertness in people traveling across time zones. These symptoms get worse with each time zone crossed, especially when traveling toward the east.
  • Shift work sleep disorder: This circadian rhythm sleep disorder affects people who frequently rotate shifts or work at night. The conflict between a person’s circadian rhythm and the time of their shift can mean they get up to four hours less sleep than the average person.
  • Delayed sleep phase syndrome (DSPS): People with DSPS have a disorder of sleep timing. They tend to fall asleep very late at night and have a hard time waking up for work, school, or social activities. DSPS is very common in teens and young adults.
  • Advanced sleep phase syndrome (ASPS): In this disorder, a person goes to sleep and wakes earlier than they want. They may fall asleep between 6-9 p.m. and wake between 1-5 a.m.
  • Non-24-hour sleep-wake disorder: This is a disorder that affects blind people. The circadian clock is set by the light-dark cycle, and with this condition, that cycle is disrupted, resulting in a serious lack of sleep at night and sleepiness during the day.


Below are some of the most common symptoms experienced by people with circadian rhythm sleep disorder. 

  • Difficulty falling asleep
  • Trouble staying asleep
  • Waking up early and not being able to get back to sleep
  • Not feeling refreshed after getting sleep


A sleep medicine specialist can make a circadian rhythm disorder diagnosis. Typically, they’ll ask you to keep a sleep journal, documenting when you went to sleep and woke up over a period of one to two weeks. If you’re unable to keep an accurate sleep journal, your doctor may recommend wrist actigraphy. This method uses a wrist monitor to measure the amount of time you’re awake and asleep. 

Your doctor may also suggest you participate in a sleep study. During the course of the study, you’ll wear a heart monitor and breathing monitor during sleep and your sleep will be observed. This will help your doctor rule out any heart or breathing issues that may be interfering with your sleep. 


There are many circadian rhythm disorder causes, from light to the level of melatonin in the body. Here are some of the most common factors:

  • Shift work
  • Time zone changes
  • Medications
  • Changes in routine, such as staying up late or sleeping in
  • Medical conditions, including Alzheimer’s or Parkinson’s disease
  • Mental health conditions
  • Menopause

Risk factors

There are also risk factors for circadian rhythm disorder. They include:

  • Congestive heart failure
  • Chronic obstructive pulmonary disease
  • Chronic pain syndromes
  • Dementia
  • Hyperthyroidism
  • Intellectual disability
  • Age
  • Family history and genetics
  • Alcohol, drug, and caffeine use
  • Gender


Circadian rhythm disorder treatment depends on the type of condition you have. In general, sleep can be improved through better sleep hygiene, including a regular nighttime routine, limiting screen time before bed, and reducing alcohol and caffeine intake. To treat your condition, medications may be used and lifestyle changes may be suggested.


Melatonin is available over the counter to treat sleep disorders. It’s a hormone that regulates sleep-wake cycles. If you have acute insomnia, your doctor may prescribe a pharmaceutical medication instead.


Certain lifestyle changes may also help treat circadian rhythm disorder. Try bright light exposure for two hours in the morning. Then commit to the following at night:

  • Perform only quiet activities, such as reading or journaling, before going to sleep
  • Avoid bright lights
  • Sleep in a quiet, comfortable room without exterior light exposure

Learn More About Circadian Rhythm from Baptist Health

Circadian rhythm disorder can be conquered. Start by scheduling an appointment with a Baptist Health primary care or sleep specialist today. 

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