Chronic Fatigue Syndrome Topic Guide

Chronic Fatigue Syndrome Chronic Fatigue Syndrome: Chronic fatigue syndrome (CFS) can also be called "systemic exertion intolerance disease," and it has no known cause. The condition is characterized by severe lethargy for more than a day after exercise or exertion. Sufferers may have a sore throat, tender lymph nodes, short-term memory problems, and grogginess even after sleeping, among other symptoms.

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