What Are Circadian Rhythm Sleep Disorders?

Circadian rhythm sleep disorders, also referred to as advanced sleep-wake phase disorder (ASWPD)—advanced sleep phase type, advanced sleep phase disorder, advanced sleep phase syndrome—involve a timing problem of when a person sleeps and is awake.

Circadian rhythms are the physical and mental changes that occur throughout the course of your day that affect whether you feel awake or sleepy. These rhythms are regulated by chemicals released in your brain in response to a stimulus, such as light. For example, you wake up in the morning because of chemicals released as your brain reacts to sunlight. Untreated individuals who try to follow conventional bedtimes may develop excessive daytime sleepiness due to a biological inability to sleep later in the morning.

Individuals with ASWPD have a biological clock that is earlier than the general population, so they naturally go to bed and wake up earlier. This disorder can run in families, and there are several genetic mutations that have been associated with this condition.

Delayed sleep phase syndrome (DSPS) is the most common type of circadian sleep disorder. People with DSPS have a tendency to stay up late at night and wake up late in the day. Delayed sleep phase syndrome can interfere with work and school because the sufferer is unable to fall asleep at regular "normal" sleep times.

Other types of circadian sleep disorders include:

  • Delayed sleep phase disorder (DSP)
  • Advanced sleep phase disorder (ASP)
  • Jet lag disorder
  • Shift work disorder
  • Irregular sleep-wake rhythm
  • Free-running (nonentrained) type

Northwestern Medicine Lake Forest Hospital Sleep Disorders Center

The Northwestern Medicine Lake Forest Hospital Sleep Disorders Center provides day and night sleep studies for diagnosis and treatment of sleep disorders, including sleep apnea, periodic limb movement disorder, nocturnal behaviors (sleep walking, talking and eating in sleep, acting out dreams) disorders and narcolepsy. Patients have the option of completing diagnostic studies at home using ambulatory monitoring technology.

Please call 847.535.8000 to schedule an appointment at our Grayslake location.

The Sleep Disorders Center also sees patients at Northwestern Memorial Hospital in downtown Chicago.

Services and Care at Northwestern Medicine Kishwaukee and Valley West Sleep Disorder Centers

The Northwestern Medicine Kishwaukee Hospital Sleep Disorder Centers conduct sleep studies to diagnose a variety of disorders in adults. The Sleep Disorder Center in DeKalb, which is an Accredited Member Center of the American Academy of Sleep Medicine, also treats children age 3 and older.

Sleep studies are performed overnight using advanced computerized equipment to monitor the brain as it transitions through the stages of sleep and measure the functions of the lungs, heart, and other parts of the body.

The Northwestern Medicine Kishwaukee Hospital Sleep Disorder Centers in DeKalb and Sandwich are trusted medical facilities known for their compassionate and excellent care. Benefits of receiving sleep studies in DeKalb and Sandwich include:

  • Highly trained polysomnographers: Each with more than 10 years of experience
  • Smooth and convenient process: For physicians who are scheduling patients and receiving reports
  • Home-like setting in private rooms: Patients sleep in a regular bed and are free to bring items from home to make bedtime comfortable