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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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