Chronic fatigue syndrome (CFS) is a complex disorder characterized by persistent fatigue that has lasted for at least six months. This fatigue is so severe that it gets in the way of normal daily activities and is not improved by rest or sleep. Any kind of physical activity or exertion leads to extreme exhaustion (a condition known as post-exertional malaise). Below you may find medications used to treat or help with Chronic Fatigue Syndrome. More about Chronic Fatigue Syndrome