Chronic Fatigue Syndrome

Chronic Fatigue Syndrome (CFS), condition manifesting as a persistent or relapsing fatigue lasting six or more consecutive months. This debilitating fatigue is characteristically accompanied by a combination of associated symptoms, including impaired concentration, short-term memory loss, muscle and joint pain, and sleep disturbances. CFS has previously been known by names such as chronic Epstein-Barr virus (EBV) disease, chronic fatigue immune dysfunction syndrome, epidemic neuromyesthenia, and myalgic encephalomyelitis.

Estimates of the incidence of CFS in the United States range from 4 to 265 of every 100,000 adults. Eighty percent of the diagnosed cases occur in white women, with the average age of onset about 30 years. There is no evidence that CFS can be transmitted from person to person, and pets do not seem to be involved in transmitting the illness.

The cause of CFS is unknown. Some viruses that can establish a chronic infection leading to fatigue and stress, such as EBV, have been implicated. Several other viruses, including human T-cell leukemia virus (HTLV), human herpesvirus-6, and enteroviruses, have also been investigated as the possible cause. Presently, CFS is diagnosed by excluding other known illnesses with similar symptoms. This method of diagnosis is controversial because it is not always possible to confirm that an individual has CFS and not some other fatigue-causing disorder, such as depression or fibromyalgia.

Supportive medications are available for relieving many of the symptoms of CFS, but some treatments can be dangerous if the diagnosis is incorrect. There is no known cure. The course of the illness varies widely among people with CFS: Some become progressively worse, some experience partial improvement, and others recover completely.