[Chronic fatigue: myth or reality?].

Chronic fatigue is one of the most common complaints. However, it can be a vexing problem in clinical practice. In contrast to serum cholesterol or blood pressure, fatigue may seem immeasurable. The management of fatigue is often complicated by the uncertainty surrounding of its cause and the frequent lack of specific therapy. Recently, criteria were established for the diagnosis of chronic fatigue syndrome. This working case definition does provide some guidance for the practicing physician.