Health Information

 

 

Non-24-Hour Sleep-Wake Disorder

National Organization for Rare Disorders, Inc.

Important

It is possible that the main title of the report Non-24-Hour Sleep-Wake Disorder is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.

Synonyms

  • free-running disorder
  • circadian rhythm sleep disorder, free-running type
  • hypernychthemeral syndrome
  • N24
  • non-24
  • non-24-hour disorder
  • non-24-hour sleep-wake syndrome
  • non-24-hour sleep-wake cycle disorder

Disorder Subdivisions

  • None

General Discussion

Non-24-hour sleep-wake disorder (N24) is a circadian rhythm sleep disorder in which an individual's biological clock fails to synchronize to a 24-hour day. Instead of sleeping at roughly the same time every day, someone with N24 will typically find their sleep time gradually delaying by minutes to hours every day. They will sleep at later and later clock times until their sleep periods go all the way around the clock. (In extremely rare cases the sleep rhythm will gradually advance rather than delay.) Patients' cycles of body temperature and hormone rhythms also follow a non-24-hour rhythm. Attempts to fight against this internal rhythm and sleep on a normal schedule result in severe and cumulative sleep deprivation.



N24 occurs in roughly 50% of completely blind people but also occurs in an unknown number of sighted people.

Resources

Circadian Sleep Disorders Network

4619 Woodfield Rd.

Bethesda, MD 20814

Email: csd-n@csd-n.org

Internet: http://www.circadiansleepdisorders.org



For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, go to www.rarediseases.org and click on Rare Disease Database under "Rare Disease Information".

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.

It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report

This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P.O. Box 1968, Danbury, CT 06813-1968; phone (203) 744-0100; web site www.rarediseases.org or email orphan@rarediseases.org

Last Updated:  3/26/2013

Copyright  2013 National Organization for Rare Disorders, Inc.

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.

Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.