Introduction

Chronic fatigue syndrome (CFS) is a disorder characterized by debilitating fatigue for at least six months duration, accompanied by a multitude of other symptoms. These symptoms are highly variable but often include a low grade fever, sore throat, tender lymph nodes, muscle pain, joint pain, headaches, sleep disturbance, depression, anxiety and cognitive dysfunction, impaired memory and/or concentration.

Objective findings are absent or insufficient to explain all these symptoms. CFS often begins after an acute flu-like respiratory or gastrointestinal illness or it may be preceded by other physical and emotional stress. In some cases, no initiating event can be identified. The symptoms are aggravated by stress and exertion.