Irregular Sleep-Wake Rhythm

Most people go to bed and sleep through the night until morning. Though the amount of sleep you get may vary from one night to the next, your sleep habits most likely fall into some kind of pattern.

For people with irregular sleep-wake rhythm, there is no predictable pattern.

Instead of sleeping through the night for a period of 6 to 8 hours, people with this disorder sleep in several shorter sessions over the course of a 24-hour period.

While they may not get all of their sleep all at once, these periodic sleep sessions generally add up to a healthy amount of sleep.

Though irregular sleep-wake rhythm is an uncommon condition, it can have a significant impact on your daily functioning and quality of life. In this article, we’ll explore the topic of irregular sleep-wake rhythm, providing an overview of this condition including its symptoms, causes, and treatment options.

What is Irregular Sleep-Wake Rhythm?

Irregular sleep-wake rhythm is often considered a sleep disorder, but it is more accurately described as a circadian rhythm disorder.

Your circadian rhythm is also known as your internal or body clock, and it dictates your sleep-wake cycle.

This cycle regulates the periods of tiredness and wakefulness you experience on a daily basis, and it generally coincides with the 24-hour cycle of night and day.

There are two categories of circadian rhythm disorders: intrinsic and extrinsic. Intrinsic disorders are those in which the patient’s internal clock is significantly different from normal.

This person may go to bed and wake up much later or earlier than usual, or their sleep may be fragmented. Extrinsic disorders are those in which the internal clock is in sync with typical day/night patterns, but school, travel, or work demands a change in sleep schedule.

Irregular sleep-wake rhythm is a condition where the patient has a sleep-wake cycle that is not defined by any regular pattern of sleep.

Instead of sleeping for an extended period of time all at once, their sleep occurs in several shorter naps throughout a 24-hour period that adds up to a total of 7 to 9 hours.

The timing and duration of these naps may vary from day to day.

This circadian rhythm disorder is challenging in a number of ways.

Many people who have it are thought to have insomnia because they have difficulty sleeping during regular nighttime hours, but they may also complain of excessive daytime sleepiness because they feel compelled to nap during the day.

This combination of symptoms makes irregular sleep-wake rhythm a challenge to diagnose, added to the fact that it is a fairly uncommon disorder.

What Are the Symptoms of Irregular Sleep-Wake Rhythm?

The defining characteristic of irregular sleep-wake rhythm is the absence of a typical circadian rhythm.

This condition is very uncommon – so much so that the exact prevalence is unknown. It seems to be most common in older adults, especially those living in nursing homes, hospitals, and other institutions.

Limited exposure to daylight and the concurrence of neurodegenerative disorders like dementia and Alzheimer’s disease may also increase your risk.

The most common symptoms of irregular sleep-wake rhythm include the following:

  • Difficulty falling asleep at night (insomnia)
  • Trouble staying asleep after falling asleep
  • Excessive daytime sleepiness
  • Strong urge or need to nap during the day
  • Short, fragmented periods of nighttime sleep
  • Several sleep periods lasting 1 to 4 hours each 24-hour period

Though people who have irregular sleep-wake rhythm don’t follow any kind of predictable sleep pattern, the disorder creates a cycle of its own.

Difficulty falling asleep and staying asleep at night leads to excessive daytime sleepiness and a strong need to nap during the day. One thing affects another and, over time, the cycle of fragmented sleep leads to chronic fatigue and decreased quality of life.

People with irregular sleep-wake rhythm typically sleep for 1 to 4 hours at a time and generally achieve 7 to 9 total hours of sleep during a 24-hour period.

Though there is relatively little research on the topic, one study from 2009 revealed that the longest period of continuous sleep typically occurs between the hours of 2am and 6am.

Daytime sleep usually consists of multiple naps.

The results of the aforementioned study also suggest that aging plays a role in the changes in circadian rhythm that contribute to irregular sleep-wake rhythm.

In addition to limited exposure to natural daylight, decreased social and physical activity during the day may also be a factor.

What Causes Irregular Sleep-Wake Rhythm?

Though people with irregular sleep-wake rhythm typically get the proper amount of sleep for their age, the fact that it is so fragmented can have a negative impact on quality of life.

Needing to take multiple naps during the day can make it difficult to hold a steady job or to succeed in school – it can also affect your relationships.

Many people who have irregular sleep-wake rhythm become homebound which can make the problem worse.

The underlying cause of irregular sleep-wake rhythm is the absence of a typical circadian rhythm. What causes this rhythm to be disrupted or absent, however, is unclear.

There are a number of things which are thought to affect the circadian rhythm which, if neglected, could potentially lead to the development of irregular sleep-wake rhythm.

Some of these things are:

  • The absence of a regular schedule for social interaction, exercise, and meals.
  • Limited exposure to natural daylight during daytime hours.
  • Genetic predisposition to variance in sleep and sleep deterioration.

Irregular sleep-wake rhythm seems to be more common in older adults, but age itself is not considered an independent risk factor.

More likely, it is the age-associated increase in neurological, psychiatric, and medical disorders that contributes most significantly to the development of irregular sleep-wake rhythm.

This condition is most common in institutionalized older adults, particularly patients with traumatic brain injury, mental retardation, dementia, or Alzheimer’s disease.

Again, there is limited research available on irregular sleep-wake rhythm which means that the underlying cause is poorly understood.

Current research is being conducted at Harvard Medical School and Brigham and Women’s Hospital to help better understand the disorder itself as well as potential causes, risk factors, and methods for diagnosis and treatment.

Testing is being conducted to determine whether measuring body temperature or melatonin levels is of clinical use in diagnosing irregular sleep-wake rhythm.

How is Irregular Sleep-Wake Rhythm Diagnosed?

Diagnosing irregular sleep-wake rhythm can be tricky for several reasons. First and foremost, it is a very uncommon disorder, so many people are unfamiliar with it.

Second, the symptoms overlap with several other sleep disorders. For example, difficulty falling or staying asleep at night is characteristic of insomnia while excessive daytime sleepiness is a symptom of several sleep disorders.

When this condition occurs in people whose work or school obligations prevents them from following a typical sleep-wake pattern, diagnosis becomes even more of a challenge.

The primary clinical feature of irregular sleep-wake rhythm is the lack of a clearly defined circadian sleep-wake rhythm.

People with this disorder exhibit at least three short bouts of sleep lasting 1 to 4 hours during a given 24-hour period.

Because the amount of sleep obtained over a 24-hour period is generally normal for the age of the patient, people who have irregular sleep-wake rhythm are technically not sleep deprived.

Diagnosis of irregular sleep-wake rhythm is made through a combination of clinical history of symptoms and a sleep diary.

Doctors look for symptoms such as a history of fragmented sleep paired with complaints of insomnia and excessive daytime sleepiness.

Your doctor may also ask you to keep a 7-day sleep diary to track period of sleep and wakefulness over several 24-hour periods.

You may also be asked to wear an actigraph which tracks your sleep-wake patterns.

In addition to a clinical history and sleep diary, your doctor may order other tests may to measure your body temperature and melatonin levels.

In most cases, an overnight sleep study is not required to make a diagnosis.

Also known as a polysomnogram, a sleep study measures your brain waves, heart rate, muscle activity, and breathing as you sleep – it is commonly used to diagnose sleep disorders.

Because a person with irregular sleep-wake rhythm experiences fragmented sleep over 24 hours rather than one long sleep overnight, polysomnography generally isn’t helpful unless your doctor is trying to determine your risk for another sleep disorder.

What Are the Treatment Options for Irregular Sleep-Wake Rhythm?

The goal of treatment for irregular sleep-wake rhythm is to correct and reset the internal clock with the hope of achieving one long period of sleep at night and one long period of wakefulness during the day.

Unfortunately, there are no simple methods of treatment. In many cases, the most effective treatment is a combination of lifestyle changes, light treatment, and other therapies such as educational and behavioral counseling.

Here are some of the lifestyle changes and therapies that might help with the treatment of irregular sleep-wake rhythm:

  • Increased exposure to light during the day. You should be exposed to both natural sunlight and blue light during the day while limiting exposure to blue light at night.
  • Supplementation with melatonin. Melatonin is a natural substance produced in the body which increases in the evening to make you tired and decreases in the morning to wake you up.
  • Following a more structured daily pattern. Including scheduled exercise and social activities in your daily pattern can help correct your circadian rhythm.
  • Improve your sleep hygiene at night. Keeping your bedroom cool, dark, and quiet can help you fall asleep and stay asleep as can minimizing the noise in your sleep environment.
  • Keeping to a schedule for sleep and meals. Going to bed and waking up at the same times each day along with regularly scheduled meals may help.

Sleep is essential but, for people with irregular sleep-wake rhythm, it doesn’t always come easily.

Though you may get an adequate amount of sleep over the course of a 24-hour period, the fragmented nature of that sleep can significantly impact your quality of life.

If you think you might have irregular sleep-wake rhythm, talk to your doctor as soon as possible.

Disclaimer: The information on this website is not intended to be used as a substitute for professional medical advice, clinical diagnosis, or treatment. Always seek the advice of your personal physician or another qualified health provider with any questions you may have regarding a medical condition.


About Kelsey Woodbridge Kelsey is a lover of anything comfy, especially her bed. In fact, you will most likely find her in her bed drafting a new article, watching New Girl, or just lounging in fuzzy socks.

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