Diagnosis of the patient with chronic pain.

The problems of classification of pain syndromes are briefly reviewed. A completely satisfactory taxonomy of pain has to be exhaustive and its categories must be mutually exclusive. This is not feasible in medicine in general and even less so in regard to pain which requires classification using several axes. Practical groupings of syndromes can be made which are helpful clinically. A list of these is provided, and principles which apply to the clinical investigation of patients with pain are stated.