Medline NLM definition: syndrome of unknown cause, characterized by clinically evaluated, unexplained persistent or relapsing chronic fatigue of at least six months' duration which is not the result of ongoing exertion; is not substantially alleviated by rest; and results in substantial reduction of previous levels of occupational, educational, social, or personal activities. Common concurrent symptoms (of six months duration) include impairment of memory or concentration, diffuse pain, sore throat, tender lymph nodes, headaches of a new type, pattern, or severity, and unrefreshing sleep. The etiology is suspected to be viral or immunologic. There are suggestions that chronic fatigue syndrome (sometimes called myalgic encephalomyelitis) may be identical to neurasthenia and fibromyalgia.
PubMed Medline search on myalgic encephalomyelitis
Myalgic Encephalomyelitis Association
Offers support for people affected by ME. Disseminates information to the general public and health professionals; campaigns for the recognition of the illness. The ME Association also has a large network of local support groups
Action for M.E.
Leading UK charity for people with Myalgic Encephalomyelitis (M.E.) and their carers. Provides information, support and advice, including the impact of ME, services and support they offer, and their policy work and research they fund.
National CFIDS Foundation (US site)
The National CFIDS Foundation, Inc., is an all-volunteer group dedicated to finding the cause and subsequent treatment of myalgic encephalomyelitis, also known as chronic fatigue syndrome and chronic fatigue immune dysfunction syndrome. The goals are to serve as an advocate for those affected by chronic fatigue syndrome, fund research, and provide accurate and timely information about this disease and related disorders.