Circadian Rhythm Disorders
Circadian rhythm disorders, also known as sleep-wake cycle disorders, are problems that occur when your body’s internal clock, which tells you when it’s time to sleep or wake, is out of sync with your environment.
Your internal clock, called a circadian clock, cycles about every 24 hours. These repeating 24-hour cycles are called the circadian rhythm.
Your body tries to align your sleep-wake cycle to cues from the environment, such as when it gets light or dark outside, when you eat, and when you are physically active. When your sleep-wake cycle is out of sync with your environment, you may have difficulty sleeping, and the quality of your sleep may be poor. Disruptions of your sleep-wake cycle that interfere with daily activities may mean that you have a circadian rhythm disorder.
Disruptions in your sleep patterns can be temporary and caused by your sleep habits, job, or travel. Or a circadian rhythm disorder can be long-term and caused by aging, your genes, or a medical condition. You may have symptoms such as extreme daytime sleepiness, decreased alertness, and problems with memory and decision-making. -----Types of Circadian Rhythm Disorders----- The types of circadian rhythm disorders are advanced or delayed sleep-wake phase disorder, irregular or non–24-hour sleep-wake rhythm disorder, and shift work or jet lag disorder. The type you may have is based on your pattern of sleep and wakefulness.
Advanced sleep-wake phase disorder
If you have advanced sleep-wake phase disorder (ASWPD), you may find it very difficult to stay awake in the early evening and as a result, wake up too early in the morning. This can interfere with work, school, or social responsibilities.
Delayed sleep-wake phase disorder
This is one of the most common circadian rhythm disorders. If you have delayed sleep-wake phase disorder (DSWPD), you may fall asleep later than you would like and then find it difficult to wake up on time in the morning. Delayed sleep-wake phase disorder often interferes with work, school, or social responsibilities. You may get too little sleep, which can lead to daytime tiredness or anxiety.
Irregular sleep-wake rhythm disorder
If you have irregular sleep-wake rhythm disorder (ISWRD), you may have several short periods of sleep and wakefulness. You may be unable to sleep during the night and take multiple naps during the day due to excessive sleepiness. You may not feel rested after sleep.
Jet lag disorder
This is often a temporary disorder that may affect you if you travel across at least two time zones in a short period. Your sleep-wake rhythm falls out of sync with the local time at your destination, so you may feel sleepy or alert at the wrong time of day or night. Jet lag disorder is often more severe when you travel east, compared to when you travel west.
Some people experience social jet lag, which can occur when you go to activities on weekends or days off at much later times than you do on weekdays or workdays. This is not considered a disorder.
Non–24-hour sleep-wake rhythm disorder
This type of circadian rhythm disorder occurs when your sleep-wake rhythm is not in sync with the 24-hour day. When this happens, your sleep times may gradually become more delayed. For example, your sleep time may be delayed to the point that you are going to sleep at noon instead of night. This often occurs when light exposure is very limited, and it is common in people who are completely blind. You may have periods of insomnia and daytime sleepiness, followed by periods with no symptoms, when your circadian rhythms happen to align with your environment.
Shift work disorder
Shift work disorder affects those who work during the night or on a rotating schedule. Because of your work schedule, you may not be able to get uninterrupted quality sleep when your body needs it. Shift work disorder can cause insomnia, extreme tiredness, and sleepiness while working at night.
Symptoms
Symptoms of circadian rhythm disorders can vary depending on the type of circadian rhythm disorder you have and how severe your condition is. Many of the symptoms of circadian rhythm disorders occur because you are not getting enough good-quality sleep when your body needs it. Undiagnosed and untreated circadian rhythm disorders may increase your risk of certain health conditions or cause workplace or road accidents. Speak with your healthcare provider to learn more about diagnosis and treatment options.
Symptoms
Difficulty falling asleep, staying asleep, or both
Excessive daytime sleepiness or sleepiness during shift work
Extreme tiredness and exhaustion
Lethargy
Decreased alertness and difficulty concentrating
Impaired judgment in risky situations, such as while driving, and trouble controlling mood and emotions
Aches and pains, including headaches
Stomach problems in people who have jet lag disorder
Treatment Options
Treatments for circadian rhythm disorders aim to reset your sleep-wake rhythm to align with your environment. Your treatment plan will depend on the type and severity of your circadian rhythm disorder. The most common treatments are healthy lifestyle changes, bright light therapy, and melatonin. Often, your doctor will recommend a combination of these treatments.
To help reset your sleep-wake cycle, your doctor may recommend that you establish a daily routine with set activities that happen during the day and another set of activities that happen at night. This may help manage the symptoms of circadian rhythm disorders.
Keep a regular meal schedule, especially if you are a shift worker or sleep at irregular times of the day or night.
Start a regular bedtime routine. Sleep in a cool, quiet place and follow a relaxing bedtime routine that limits stress. These practices, along with regular sleep and waking times, can help you fall asleep faster and stay asleep longer.
Avoid daytime naps, especially in the afternoon. However, shift workers may benefit from a short nap before the start of their shift.
Get regular physical activity. Your doctor may recommend getting regular physical activity during the daytime and avoiding exercising close to bedtime, which may make it hard to fall asleep.
Limit caffeine, alcohol, nicotine, and some medicines, especially close to bedtime.
Manage your exposure to light. Light is the strongest signal in the environment to help reset your sleep-wake cycle. You may need more sunlight during the day and less artificial light at night from TV screens and electronic devices. Artificial light can lower your melatonin levels, making it harder to fall asleep. Light-blocking glasses, screen filters, or smartphone apps can help dim the light from your electronic devices. Dim lighting for a period before bed may also help reduce the symptoms of a circadian rhythm disorder. For shift workers, wearing light-blocking glasses when you are outside during the day may help.
Light therapy
Your doctor may suggest that you try light therapy to treat some types of circadian rhythm disorders. With this approach, you plan time each day to sit in front of a light box, which produces bright light similar to sunlight. Light visors and light glasses may also be effective. Light therapy may help adjust how much melatonin your body makes to reset your sleep-wake cycle.
To move your sleep and wake times earlier, use the light box when you wake up in the morning. This may also help reduce daytime sleepiness. This method may be used to help treat delayed sleep-wake phase disorder, irregular sleep-wake rhythm disorder, and jet lag disorder when you travel east.
To move your sleep and wake times later, use the light box late in the afternoon or early in the evening. This method may be used to help treat advanced sleep-wake phase disorder, shift work disorder, and jet lag disorder when you travel west.
Side effects of light therapy may include agitation, eye strain, headaches, migraines, and nausea. Ask your doctor before using light therapy if you have an eye condition or use medicines that make you sensitive to light.
Medicines or supplements
Your doctor may recommend melatonin medicines or supplements to help align your sleep-wake cycle with your environment.
Melatonin medicine, called melatonin receptor agonists, can help treat non–24-hour sleep-wake rhythm disorder. Side effects can include dizziness and fatigue.
Melatonin supplements are lab-made versions of the sleep hormone that your doctor may recommend for delayed sleep-wake phase disorder, irregular sleep-wake rhythm disorder, and non–24-hour sleep-wake rhythm disorder. These supplements are not regulated by the U.S. Food and Drug Administration. Because of this, the dose and purity of these supplements can vary between brands. Talk with your doctor about how to find safe, effective melatonin supplements, as well as any possible side effects or medicine interactions, especially if you are pregnant or trying to become pregnant. Side effects of melatonin may include excess sleepiness, headaches, high blood pressure, low blood pressure, stomach upsets, and worsening symptoms of depression.
Your doctor may talk to you about other ways to treat the symptoms of circadian rhythm disorders.
Caffeine may help prevent daytime sleepiness. Your doctor may recommend that you avoid caffeine within eight hours of your desired bedtime.
Sleep-promoting medicines, such as benzodiazepines and zolpidem, can help you fall asleep faster and stay asleep longer. These medicines may cause side effects and complications, such as muscle weakness and confusion, that may be more severe in older adults and people who have dementia.
Wake-promoting medicines, such as modafinil and armodafinil, can help you stay alert and improve performance during shift work. The effects of these medicines may last only for a short time, and you may still experience some sleepiness.