Chronic fatigue syndrome is a clinical condition characterized by abnormal fatigue, subfebrile body temperature, sore throat, lymphadenopathy, arthralgia, myalgia and neuropsychiatric symptoms. Typically, the syndrome develops after a flu-like illness and is markedly exacerbated by exercise. The etiology is unknown and there is no single diagnostic test. The patients may have cognitive dysfunction, immunological and endocrinological abnormalities and abnormal mitochondria. Magnetic resonance imaging scans may show increased uptake of signals in the brain, and single photon emission computerized tomography reveals regional hypoperfusion of the brain. The author discusses similarities and distinctions between the syndrome and depression.
