The Centers for Disease Control estimates that one million people in the US have chronic fatigue syndrome (CFS) and as many as 17-24 million people worldwide have CFS.

Chronic fatigue syndrome is a complex and debilitating condition characterized by fatigue that lasts for at least six months and can’t fully be explained by an underlying medical condition. The fatigue is so severe that it gets in the way of normal daily activities at home and at work. Rest and sleep do not help reduce the level of fatigue. It is accompanied by other symptoms such as headaches, sleep disturbance, cognitive difficulties, and muscle pain. Routine physical activity can leave you feeling worse, causing post-exertional malaise.

The severity of the symptoms varies widely between patients. Currently, there is no cure for CFS, and treatment focuses only on ameliorating symptoms.