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HomeHealth articlescircadian rhythm sleep disorderCircadian Rhythm Sleep Disorder | Types | Symptoms | Risk | Diagnosis | Treatment

Circadian Rhythm Sleep Disorder - Types, Symptoms, Risk, Diagnosis and Treatment

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A disruption in your sleep-wake cycle causes circadian rhythm sleep disorder. Learn the causes, types, and ways to manage one in this article.

Medically reviewed by

Dr. Mohammed Abdul Nasir

Published At April 5, 2022
Reviewed AtNovember 24, 2023

What Is Circadian Rhythm?

Circadian rhythm, a term derived from the Latin phrase “circa diem” meaning “around a day,” is an internal rhythm, cycle, or clock of the body that works to ensure that all bodily processes happen at the right time whenever they should for smooth functioning of the body. A part of the brain, the hypothalamus (suprachiasmatic nucleus [cluster of proteins] to be specific), sends signals to the body to regulate activities, thereby maintaining the circadian rhythm.

The sleep-wake cycle is one of the best-known circadian rhythms. It is a 24-hour internal clock of the body that controls daily sleep and wakefulness. External factors like light, dark, physical activity, medications, traveling through different zones, night work shifts, stress, mental health, excessive screen time, etc., influence the circadian rhythm.

What Is Circadian Rhythm Sleep Disorder?

When a person’s sleep-wake cycle gets disrupted due to a misalignment in the body’s internal clock and external environment impacting daily activities, the condition is called circadian rhythm sleep disorder. The body’s biological clock or timing determining when one should sleep and wake is affected, leading to problems with sleeping, falling asleep, staying asleep, and waking up.

What Problems Do People With Circadian Rhythm Sleep Disorder Undergo?

The sleep-wake difficulties faced by the affected individual include;

  • Excessive daytime sleepiness.

  • Difficulty initiating sleep.

  • Difficulty staying asleep (waking up too early).

  • Sleep disturbances (waking up frequently at night).

  • Problems maintaining sound sleep (poor sleep quality).

What Symptoms Do People With Circadian Rhythm Sleep Disorder Experience?

There are several types of circadian rhythm sleep disorders (discussed further) based on which the symptoms vary. But usually, they include;

  • Lethargy.

  • Diminished vigilance or alertness.

  • Stomach aches.

  • Headache.

  • Fatigue.

  • Poor concentration.

  • Problems controlling emotions.

  • Difficulty initiating sleep or waking up (or both).

What Are the Types of Circadian Rhythm Sleep Disorders?

Six types of this disorder exist;

  • Delayed Sleep Phase Disorder (DSP) - In this type, the person goes to sleep more than two hours after the normal sleeping time (like 3 AM) and gets up late in the morning (like 10 AM or afternoon) or finds it difficult to get up on time. Such people are often referred to as “night owls.” More adolescents and young adults have this type of sleep disorder. These people are different from those who stay awake late at night by choice whenever required for some purpose like meeting deadlines, finishing important pending works, etc.

  • Advanced Sleep Phase Disorder (ASP) - People with this type of disorder go to sleep (between 6 PM and 9 PM) and get up (2 AM and 5 AM) several hours earlier than the normal timings. Middle-aged and elderly have this type more frequently, and the prevalence increases with aging. Such people are referred to as “morning types.”

  • Jet Lag Disorder - People traveling by airplanes over long distances experience shifting time zones.

“For example, a person traveling to the United States from India has to travel approximately 20 hours. The time difference between India and the United States is 10 hours 30 minutes (India is ahead). If a person boarded the flight by 9 AM in India, they would reach the United States at 5 AM as per Indian time the next day. But it would be 6.30 PM in the United States. It means the person would have slept and woke up already according to Indian time, but as they land, they find themselves in the night atmosphere.”

The body’s clock gets confused between day and night, light and dark. This misalignment is temporary, and the circadian rhythm soon gets aligned to the new time zone. Until then, they fall asleep and wake up at the wrong times and feel fatigued and exhausted. Eastward travel and crossing two or more time zones within a short span increase the severity.

  • Shift Work Disorder - People working night shifts, rotating shifts, and early morning shifts have difficulty staying awake at night during work and falling asleep during the day. People with comorbidities have an increased risk of their condition exacerbating and worsening with altered circadian rhythms and poor sleep.

  • Irregular Sleep-Wake Rhythm - Such people with this disorder have fragmented sleep in the form of naps throughout the day and at night. They have an undefined circadian sleep rhythm and feel tired due to poor quality and quantity of sleep.

  • Free-Running (Nonentrained) Type - Due to a lack of visual cues (daylight exposure) in people with visual impairment and nursing school residents, there is a shift in the sleep-wake cycle such that they go to sleep at noon and get up at night.

What Risks Are Associated With Circadian Rhythm Sleep Disorder?

Sleep disturbances and inconsistent sleep patterns are often underestimated and can be risky if ignored. Some complications they could cause can cost the lives of the affected people. There is a risk of;

  • Accidents at the workplace or on roads.

  • Developing increased blood pressure (hypertension).

  • Cardiovascular diseases (atherosclerosis or stroke).

  • Metabolic syndrome.

  • Diabetes.

  • Obesity.

  • Anxiety and depression.

  • Cognitive disorders.

  • Weak immune system.

  • Worsening of existing sleep disorders, if any.

  • Low performance in studies and work due to sleep deprivation.

  • Mental, physical, and social impairment due to sleep disturbances.

How Are Circadian Rhythm Sleep Disorders Diagnosed?

  • A sleep medicine specialist will be able to diagnose the condition. Your doctor will take a detailed medical history and ask about your sleep pattern and duration, medications you are taking, preexisting sleep disorders (like sleep apnea, narcolepsy, etc.), caffeine consumption levels, nicotine and alcohol usage, etc.

  • You will be asked to maintain a sleep journal wherein you would have to note down your sleeping and waking up timings.

  • Actigraph or actometer, a wrist monitor that helps track your sleep-wake cycle, must be worn.

  • Sleep studies (polysomnography) will also be conducted to monitor your sleep.

  • Your melatonin and cortisol levels will also be checked.

What Treatments Help Restore Circadian Sleep Rhythm?

  • Lifestyle Changes -

  1. Avoid daytime naps. But if you are a night shift worker, a nap before your work time will benefit you.

  2. Exercise regularly.

  3. Stick to a sleep-inducing bedtime routine (sleep hygiene).

  4. Limit or avoid the intake of caffeinated foods and beverages, alcohol, and nicotine after the evening.

  5. Sunlight exposure during the day and limiting the use of blue light-emitting devices such as laptops, smartphones, etc., are also beneficial in resetting the circadian rhythm.

  • Bright Light Therapy - In this therapy, the eyes are exposed to safe levels of bright light at some intervals for a short duration. You might need to sit in front of a lightbox that emits the light or have to wear light visors or glasses.

  • Melatonin Supplements - Melatonin is a hormone that our body produces at night. It induces and promotes sleep. Lab-made versions of this hormone are used to treat sleep-wake rhythm disorders.

  • Other Medications - Hypnotics, caffeine, beta-blockers, stimulants such as Modafinil, and sleep-promoting drugs such as Benzodiazepines are given based on the type of disorder to induce sleep at night and prevent daytime sleepiness.


Though improper sleep due to sleeping disorders might seem a minor issue initially, the possibility of developing life-threatening consequences such as road traffic accidents, heart problems, weakened immunity, etc., cannot be denied. One’s everyday life gets disrupted in every aspect if adequate sleep is not achieved. Do not underestimate sleep disorders and immediately seek an online specialist’s help if you have one.

Frequently Asked Questions


How Can Circadian Rhythm Sleep Order Be Managed?

Circadian rhythm can be treated based on the type of disorder and health status. The treatment includes:
- Lifestyle Changes: Sleeping, avoiding naps, routine exercise, avoiding alcohol, nicotine, and smoking improves the disorder.
- Bright Light Therapy: The therapy includes exposure to bright light in the morning, and resetting the circadian clock may help with the condition. The doctor may prescribe decreasing the light exposure during evening and night. Avoid bright TV lights and computer screens.
- Medications: The doctor may prescribe medications like Modafinil, and Melatonin to improve the sleep-wake-cycle. 


How Can Circadian Rhythm Disorder Be Diagnosed?

The healthcare provider may ask for information about sleep history. The doctor may use some tests to identify the disorder. They may advise the patient to write down the time for sleep in the diary for one or two weeks. The disease can be diagnosed by measuring the oxygen level. 


What Are the Types of Sleep Disorders?

The common types include:
- Delayed type sleep disorder - If the person sleeps late at night.
- Advanced phase sleep disorder - If the person sleeps early in the evening and wakes up in the early morning.
- Shift work disorder - The person works at night and sleeps during the day.
- Irregular sleep-wake rhythm - The person may take several naps during the day.
- Non-24-hour sleep-wake syndrome - The length of sleep and awake time are the same.


Which Hormone Regulates the Sleep-Wake Cycle?

The main center is the brain, which tells the time to sleep. Light and darkness help in determining the sleep and wake cycle. The pineal gland located in the brain triggers the release of melatonin. The melatonin hormone helps the person to feel sleepy.


Which Is the Most Common Sleep Disorder?

Insomnia is the most common sleep disorder. Insomnia is defined as the person’s inability to maintain and initiate sleep.


What Causes the Person to Wake Up in the Middle of the Night?

Insomnia makes the person wake up in the middle of the night. Drinking coffee, stress, alcohol, sleep disorders, poor sleep environment, and health conditions cause the person to wake up in the middle of the night.


Which Organ Controls Circadian Rhythm?

The main organ is the brain, which controls the circadian rhythm. The small nuclei in the middle of the brain regulate the circadian rhythm. They are known as suprachiasmatic nuclei. These nuclei are connected to the other parts of the brain.


Which Hormones Cause Sleep Disorders?

The hormones that cause sleep disorders are as follows:
- Cortisol. 
- Growth hormone.
- Leptin.
- Ghrelin and melatonin are linked with sleep and circadian rhythms.
Source Article IclonSourcesSource Article Arrow
Dr. Mohammed Abdul Nasir
Dr. Mohammed Abdul Nasir

Pain Medicine


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