Postviral fatigue syndrome.

Myalgic Encephalomyelitis or post-viral fatigue syndrome is a common disorder, which has been known previously under a variety of different names, i.e., Iceland disease or Royal Free disease. It may occur in epidemics or sporadically. The cause is unknown, with patients complaining of exhaustion, fatigue, muscle aches and pains, and invariable psychiatric symptoms such as emotional lability, poor memory/concentration, and depression. Present-day research points to the cause as a metabolic disorder secondary to persistent viral infection.