Circadian Rhythm Disorders2020-12-11T10:15:44-07:00

Circadian Rhythm Disorders

Circadian Rhythm Sleep-Wake Disorders are a collection of disorders that can occur when your typical sleep times are misaligned. The Insomnia and Sleep Institute of Arizona is recognized as the Face of Sleep Medicine in the Phoenix Area, staffed by sleep specialists concentrating in sleep medicine. Any time you struggle with sleep and the resulting symptoms of grogginess, lack of concentration, anxiety, and more, the best approach is to work with the leaders in sleep medicine.

Our unique circadian rhythms are powerful, but not immune to expert adjustment. Help and treatment are available for those struggling with these types of sleep disorders, and it begins with a correct diagnosis.

There are a number of circadian rhythm sleep-wake disorders.

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Shift work sleep phase disorder

Shift work sleep phase disorder affects those who have a non-traditional work schedule, such as an overnight shift or even work the second shift, can cause what is known as shift work disorder. This results in poor sleep and exhaustion during waking hours.

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Irregular sleep-wake disorder

Irregular sleep-wake disorder happens when a person’s circadian rhythm is so disorganized that no sleep-wake pattern is clear. Some patients might nap routinely rather than sleep a longer stretch during a 24-hour period.

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Jet lag

Many people have experienced jet lag. It naturally happens if you travel across at least three time zones from your home time zone and struggle to adjust to a new schedule.

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Advanced sleep-wake phase disorder

Advanced sleep-wake phase circadian rhythm disorder happens when a person falls asleep many hours after their normal bedtime and wakes up several hours earlier than normal—often in the middle of the night. This often occurs when a person travels internationally.

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Delayed sleep-wake phase disorder

Delayed sleep-wake phase disorder occurs when a sleep pattern is delayed by a minimum of two hours. In other words, when a person goes to sleep two hours later than normal and wakes up two hours later than their usual time, this is an example of a delayed sleep-wake phase. It most often occurs temporarily, such as when a person attends an evening event.

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Non-24-hour / Free running circadian rhythm disorder

Non-24-hour / Free running circadian rhythm disorder is when a person has this disorder, their sleep schedule changes a little day to day. Eventually, their sleep times might be completely out of alignment with their daily activities or sleep partner’s schedule.  This disorder is typically limited to individuals that are blind and/or do not have light perception and hence the brain loses the ability to no when it is daytime and night.

Circadian Rythm Disorders and Your Health

The exact causes, symptoms, and risk factors vary person to person and disorder by the disorder. Generally shared symptoms include fatigue, grogginess, trouble concentrating, and struggling to stay alert when a person should be awake and energized. It is also important to consider whether another sleep disorder might be occurring, such as sleep apnea. Medications, substance use or abuse, medical conditions including obesity, hormone shifts such as during menopause, and mental health disorders can also cause or exacerbate some sleep disorders. Of course, there are also instances where a person knows the cause of their short-term sleep disorder, such as a change in their work shift or traveling.

Treatments For Circadian Rhythm Disorders

Therapeutic options for circadian rhythm disorders depend upon the type of disorder and some possibilities include:

  • Delayed sleep-wake phase disorder: CBT-I with progressive advancement or delay of the circadian rhythm including the strategic use of melatonin and light therapy.
  • Advanced sleep-wake phase disorder: CBT-I with progressive delay of the circadian rhythm with strategic use of light therapy.
  • Shift work sleep disorder: CBT-I for fostering sleep and to address sleep onset insomnia in addition to behavioral strategies to minimize light exposure after finishing the night shift, strategic use of melatonin, and consideration of the use of wake-promoting agents during the night shift if the patient is having difficulty maintaining alertness while working or driving home.
  • Non-24-hour / Free running circadian rhythm disorder: this disorder occurs in individuals that have lost light perception; strategic use of melatonin to lock-in the circadian rhythm versus the use of a prescription medication known as Hetlioz.
  • Jet lag: strategic use of melatonin, natural light exposure, and bright light therapy.


I have no choice but to adjust to a new shift schedule. Is there anything I can do?2020-12-02T09:13:29-07:00

Absolutely. Working with a leading sleep specialist is the first step for frequent travelers and shift workers who simply must adjust their circadian rhythm. There are numerous options for shift workers, including CBT-I therapy. Sleep scheduling, improving daytime sleep, sleep hygiene, melatonin, expert-directed napping, and caffeine as well as sleep and wake agents can all be helpful.

Can you really avoid jet lag?2020-12-02T09:12:25-07:00

Many patients can effectively decrease or even prevent jet lag with proper preparation. This may include bright light therapy up to three days before departure, slowly shifting bedtimes by an hour each night to mimic the upcoming sleep cycle, and strategic light exposure/avoidance upon arrival to help the circadian rhythm adjust.

How does a sleep specialist diagnose these disorders?2020-12-02T09:11:59-07:00

It depends on numerous factors including which circadian rhythm disorder might be present that are discovered upon the clinical history our sleep specialist obtains during the consultation. For example, in the non-24-hour sleep-wake rhythm disorder, diagnostic criteria can include a history of insomnia and/or excessive daytime sleepiness, symptoms lasting over 3 months, and ultimately a lack of other conditions or causes of the condition (such as medications).

What exactly is the circadian rhythm?2020-12-02T09:11:01-07:00

Everyone has an intrinsic circadian rhythm, which is an internal timekeeper that helps manage a number of our systems in a 24-hour period. This includes key factors like body temperature, appetite, and cortisol levels. This system is what drives our wakefulness during our own, habitual waking day in order to ward off sleepiness.