The treatment of fatigue.

Fatigue is a psychophysiological state that acts on the subject's motivation to engage in and/or to continue strenuous physical or cognitive activities. In various pathological conditions fatigue seems to lose this homeostatic function and presents itself as a symptom. The pathophysiology of fatigue is complex and includes neurological (central and peripheral) dysfunction, and altered neurotransmitter, cytokine, and hormonal settings. Treatment interventions are generally based on a sequential approach including treatment of comorbid factors, nonpharmacological treatments, and drugs.