Circadian Rhythm Sleep Disorders

Humans have an internal biological clock that helps our bodies operate on a roughly 24-hour rhythm. These circadian rhythms are particularly important to help us sleep at night and stay awake during the day. Circadian rhythm sleep disorders occur when either our internal clock does not match the world around us or when our biological clock is not working properly. A classic example of a disorder stemming from a mismatch between the internal circadian clock and the environment is shift work.


Shift work sleep disorder can occur when individuals are required to be awake during normal sleep hours and asleep during normal waking hours. This can result in lower quality and quantity of sleep as well as impaired performance and disturbed mood. A common disorder in which the internal clock is operating abnormally is delayed phase sleep disorder.


In this disorder, a person’s internal clock is set to sleep and wake times that occur much later than usual. This can lead to bedtimes and waking times several hours later than conventional or desired, with some individuals unable to fall asleep until as late as 5 or 6am. A range of treatment options are available for these sleep problems. Most focus on aligning the body’s circadian rhythm with the work/sleep schedule, optimizing functioning during waking hours and improving sleep quality.


Shift Work and Sleep

Coping with shift work can be challenging. Though the most problematic symptoms associated with shift work vary from person to person, the following recommendations are often helpful:


Your sleep schedule:

  • Schedule adequate hours in bed for sleep every day
  • Use days off to catch up on sleep
  • On days off, schedule your sleep time so that it overlaps at least partially with the hours you sleep during workdays

Negotiate with your employer:

  • Minimize the number of consecutive night shifts
  • If you have rotating shifts, schedule shifts to rotate clockwise (e.g., going from second to third shift, rather than third to second shift, etc.)

If you experience sleepiness during your shift:

  • Take a nap before the start of your shift
  • Have caffeine just prior to starting your shift
  • Expose yourself to bright light in the workplace, if possible

For problems sleeping during the day:

  • Keep your bedroom dark; use blackout curtains or an eye cover
  • Minimize noises that may interfere with your sleep; earplugs can be effective for some people
  • Use blue light blocking goggles or sunglasses to minimize light exposure in the morning following night shift work (not recommended if you have difficulty staying alert during your drive home from work)
  • If you have a regular schedule/routine during your shift work, try melatonin (0.5-1mg) before going to sleep

If problems with insomnia and/or sleepiness are still an issue for you, talk with your provider about prescription medications that might be helpful for you.


Additional Information on Circadian Rhythm Sleep Disorders