Chronic fatigue syndrome: issues in the diagnosis and estimation of incidence.

This article critiques the current working definition of chronic fatigue syndrome. The concerns raised about the current working definition are the following: prolonged or excessive exertion is not addressed explicitly; duration and quality of bed rest are not specified; a socioeconomic ascertainment bias is present; data from history and physical findings are not clearly separated and are relegated to minor criteria; and the rigor of neurologic and psychiatric evaluations is not specified. We propose a flow chart that addresses the possible modes of evolution of chronic fatigue syndrome for patients; this chart may yield more homogeneous subgroups of individuals with this syndrome or enable some patients to avert the syndrome.