- MEDICAL CONDITION
Chronic fatigue syndrome, or CFS, is a devastating and complex disorder. People with CFS have overwhelming fatigue and a host of other symptoms that are not improved by bed rest and that can get worse after physical activity or mental exertion. They often function at a substantially lower level of activity than they were capable of before they became ill.
Besides severe fatigue, other symptoms include muscle pain, impaired memory or mental concentration, insomnia, and post-exertion malaise lasting more than 24 hours. In some cases, CFS can persist for years.
Researchers have not yet identified what causes CFS, and there are no tests to diagnose CFS. Moreover, because many illnesses have fatigue as a symptom, doctors need to take care to rule out other conditions, which may be treatable.