How Circadian Rhythm Disorders Can Affect Your Sleep

An out-of-sync body clock does more than just leave you sleepy. It can affect your heart health, mood, and performance at work and school. Here's how to get your rhythm back in line.

You just can’t seem to get to bed before 2 a.m. Or maybe the opposite happens: You wake up at 3 a.m., ready to start your day. Then again, it could be shift work that’s keeping you up at night and forcing you to grab some sleep during the day, leaving you perpetually fatigued.

All of these are examples of circadian rhythm disorders, which are problems with the alignment between your sleep-wake cycle and your responsibilities for the day—like going to work or school, or seeing friends.

Research suggests that about 3 percent of adults have some type of circadian rhythm disorder.

What causes circadian rhythm disorder?

“The circadian rhythm is the body’s internal clock,” says Lawrence Jay Epstein, MD, clinical director of the division of sleep and circadian disorders at Brigham and Women’s Hospital in Boston. “It regulates all of the physiologic processes in the body.”

It affects your whole body, but most notably your sleep. When your circadian rhythm is in balance, you go to sleep at a normal time and you stay asleep throughout the night. However, “when the circadian rhythm becomes misaligned in any way, you start to suffer from sleep problems,” says Dr. Epstein.

This can happen because of lifestyle—say, for instance, your job requires you to work in the middle of the night, or you’ve taken an international flight and now you’re suffering from jet lag. It can also happen because of your innate circadian rhythm. In other words: It’s just how you are.

That can be genetically determined, but age also plays a role, says Marissa Bowman with the Center for Sleep & Circadian Science at the University of Pittsburgh. “During adolescence, we see that teens tend to prefer to go to bed later and later, which is often in conflict with the early times they have to wake up for school. During older age, we see that (people) often prefer to go to bed earlier,” she explains.

African american girl closed eyes with hands in bedProstock-Studio/Getty Images

Different types of circadian rhythm disorder

There are several types of circadian rhythm disorders, notes the National Institutes of Health. They include:

Advanced sleep-wake phase disorder: It’s difficult to stay awake in the early evening, and you wake up unusually early in the morning.

Delayed sleep-wake phase disorder: You stay up late into the night and have trouble waking up on time for responsibilities in the morning.

Irregular sleep-wake rhythm disorder: You sleep in small bursts throughout the day and night and generally suffer from sleepiness.

Jet lag disorder: You feel sleepy or awake at the wrong time after traveling across at least two time zones. This is short-term; your clock will eventually sync with local time. What’s known as “social jet lag” can happen on weekends when you stay up and sleep in later than you do on weekdays.

Non-24-hour sleep-wake rhythm disorder: Your sleep-wake patterns do not follow a 24-hour day. As a result, your clock gradually shifts, leading to insomnia followed by periods of totally normal sleep. This happens to people who are blind.

Shift work disorder: Happens after working during the night or on a rotating schedule.

Signs and symptoms of circadian rhythm disorders

You notice that your sleep patterns don’t match up with what you have going on in your life. But it’s not really a problem until, well, it causes a problem in your day-to-day life, how you feel, or your relationships with others. “A characteristic for diagnosis is clinical distress or impairment,” says Bowman.

Here’s what to look for:

  • Feeling sleepy
  • Not feeling well-rested
  • Having difficulty concentrating
  • Irritability
  • A low mood
  • Depression
  • Problems in work or school
  • Substance abuse

Diagnosing circadian rhythm disorder

To diagnose any sleep problem, your doctor—ideally a sleep specialist—will take your medical history and do a clinical examination to establish your sleep and wake patterns, Dr. Epstein says. They will also look for signs and symptoms of other sleep disorders that have similar symptoms (like insomnia) and rule those out. Your provider can also run a test that determines at what time your body releases the hormone melatonin, which essentially makes you sleepy at night.

If your doctor thinks it could be sleep apnea or a limb movement disorder, then they might order a sleep study to check for the  underlying cause.

If there’s suspicion of a circadian rhythm disorder, then you might be asked to keep a sleep diary for several weeks to get a full picture of your habits, Dr. Epstein says. That’s when you keep a log of sleeping habits, as well as other factors like caffeine and alcohol intake. Wearables like Apple Watch, Fitbit, or Garmin can provide similar data, he says. The only limitation is that these are not 100 percent accurate.

Treatment for circadian rhythm disorder 

When you have a circadian rhythm disorder, you have two options for treatment, says Dr. Epstein. You can change your schedule to match your innate circadian pattern. Or you can try to change your circadian pattern.

In other words, if you are a night owl and wake up at noon, then a job that starts a shift later in the afternoon might be more fitting for you and work better with your sleep-wake habits. But if you have to get up early to be at a 9-to-5 job—or maybe you simply don’t want to go to bed at an early hour because you like to participate in social activities in the evening—then shifting your circadian rhythm is in order.

How to shift your circadian rhythm

Treatment includes light exposure (bright light therapy), plus light control and sleep hygiene, along with melatonin.

In simple terms, light exposure resets your body’s clock. For example: If you have a delayed sleep-wake phase disorder, you would use bright light in the morning. At the lab, Bowman recommends that patients use a light box that is 2,500 to 10,000 lux for 30 to 60 minutes within the first hour of waking up.

In the evening, you would limit or avoid light, which means reducing time spent in front of the TV or computer. Bowman also recommends good sleep hygiene habits, like developing a wind-down routine before bed with relaxing activities and maintaining a consistent sleep-wake schedule.

Your doctor might suggest taking a melatonin supplement one to two hours before your desired bedtime, Dr. Epstein says. Melatonin is the sleep-promoting hormone that your body naturally releases at night. Well-timed melatonin supplements will help shift your body’s clock.

Taken together, these things would shift your sleep-wake cycle and help you adjust the habits that are actively keeping you up, so that you can go to bed and wake up earlier.

It’s key to seek help from a trained sleep medicine physician. You’ll want the right exposure of light at the right time, along with the proper dose of melatonin to produce the results you’re looking for to treat your specific disorder. Otherwise, you could shift things in the wrong direction, Dr. Epstein says.

Outlook for circadian rhythm disorder

Problems arise with untreated circadian rhythm disorder. Not because it’s necessarily dangerous to be a severe early bird or night owl, but because a desynchronized clock leads to poor sleep. “Sleep deprivation leads to other medical problems like hypertension, heart disease, diabetes, and obesity,” Dr. Epstein says. It can also lead to safety problems, like car accidents.

Treatment doesn’t result in permanent change—unless you stick with it. “This is something that’s a genetically determined pattern,” notes Dr. Epstein. “You can do things to shift your clock, but it requires ongoing management.”

Maintaining this new shift is a challenge for many patients. If, for instance, you stay up late on the weekends, then Sunday, you’ll have trouble going to sleep and you’ll be back at square one. “It’s best to maintain your new schedule throughout the week, but really try to avoid [staying up or sleeping in] more than one hour on the weekend,” he says.

Even if things slide backwards, there’s still hope. “It’s common for patients to later experience a drift in their rhythms back to where it was pre-treatment, and that’s OK,” says Bowman. By using the strategies you’ve learned and making small adjustments again, you can get back on track, she says.

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Jessica Migala
Jessica Migala is a freelance health and fitness writer with more than a decade experience reporting on wellness trends and research. She's contributed to Health, Men's Health, Family Circle, Woman's Day, and O, The Oprah Magazine, among other publications. Jessica lives with her husband and two young sons in the Chicago suburbs.