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Brain & Nervous System Health Center

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Chronic Fatigue Syndrome/Myalgic Encephalomyelitis

It is possible that the main title of the report Chronic Fatigue Syndrome/Myalgic Encephalomyelitis 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.


  • Akureyri Disease
  • Benign Myalgic Encephalomyelitis
  • Epidemic Myalgic Encephalomyelitis
  • Epidemic Neuromyasthenia
  • Iceland Disease
  • Raphe Nucleus Encephalopathy
  • Royal Free Disease
  • Tapanui Flu
  • CFS
  • ME

Disorder Subdivisions

  • None

General Discussion

Until the late 1980s, myalgic encephalomyelitis was thought to be a distinct, infectious disorder affecting the central, peripheral and autonomic nervous systems and the muscles. Its major symptom was fatigue to the point of extended periods of exhaustion. A group of experts studying the Epstein-Barr virus first published strict criteria for the symptoms and physical signs of chronic fatigue syndrome in 1988. This case definition was further refined in 1994.

The Fact Sheet for CFS published by the National Institutes of Allergy and Infectious Diseases of the National Institutes of Health states that "[T]oday, CFS is also known as myalgic encephalomyelitis, postviral fatigue syndrome, and chronic fatigue and immune dysfunction syndrome." ME/CFS is now recognized as part of a range of illnesses that have fatigue as a major symptom.

ME/CFS is not rare. The CDC estimates that there are as many as 500,000 persons in the United States who have CFS-like symptoms. However, the disorder remains debilitating, complex and mysterious in origin, natural history, understanding and treatment.


National Chronic Fatigue Syndrome & Fibromyalgia Association
P.O. Box 18426
Kansas City, MO 64133
Tel: (816)737-1343
Fax: (816)524-6782

ME Association
7 Apollo Office Court
Radclive Road
Bucks, MK18 4DF
United Kingdom
Tel: 01280818964

Centers for Disease Control and Prevention
1600 Clifton Road NE
Atlanta, GA 30333
Tel: (404)639-3534
Tel: (800)232-4636
TDD: (888)232-6348

NIH/National Institute of Allergy and Infectious Diseases
Office of Communications and Government Relations
6610 Rockledge Drive, MSC 6612
Bethesda, MD 20892-6612
Tel: (301)496-5717
Fax: (301)402-3573
Tel: (866)284-4107
TDD: (800)877-8339

CFIDS Association of America
PO Box 220398
Charlotte, NC 28222-0398
Tel: (704)365-2343
Fax: (704)365-9755
Tel: (800)442-3437

MAME, Inc. (Mothers Against Myalgic Encephalomyelitis)
1 Orne Square
Salem, MA 01970
Tel: (978)744-8293
Fax: (978)744-2027

National CFIDS Foundation, Inc.
103 Aletha Road
Needham, MA 02492-3931
Tel: (781)449-3535
Fax: (781)449-8606

P.O. Box 9204
Bardonia, NY 10954
Tel: (914)648-9197
Fax: (845)215-0041

Genetic and Rare Diseases (GARD) Information Center
PO Box 8126
Gaithersburg, MD 20898-8126
Tel: (301)251-4925
Fax: (301)251-4911
Tel: (888)205-2311
TDD: (888)205-3223

ME Research UK
The Gateway
North Methven Street
Perth, PH1 5PP
United Kingdom
Tel: 01738451234

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 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 or email

Last Updated: 4/8/2009
Copyright 1987, 1988, 1989, 2004, 2009 National Organization for Rare Disorders, Inc.

WebMD Medical Reference from the National Organization for Rare Disorders

Last Updated: May 28, 2015
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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