[Chronic fatigue syndrome: the point of view of the internist].

Chronic fatigue is a very common symptom in primary care medicine. Psychiatric causes represent more than 80% of the cases. After excluding all known causes of fatigue, 30% of the patients remain without a specific diagnosis and suffered from idiopathic chronic fatigue. The chronic fatigue syndrome (CFS) which represents a very small subset of these patients is a heterogeneous disorder characterized by fatigue, neuropsychiatric symptoms, and various other somatic complaints. The cause remains underdetermined and most of the treatments are ineffective. Antidepressants drugs may be helpful. A supportive approach, cognitive behavioural therapy and graded exercise seem so far the only evidence-based therapeutic approach.