Chronic Fatigue Syndrome (CFS): 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.
Chronic Fatigue FAQs Is it all in the mind? Get answers to frequently asked questions (FAQs) about chronic fatigue syndrome (CFS), a complex, debilitating illness that leaves exhausted people in its wake.