This report proposes that reflex sympathetic dystrophy be defined as a pain syndrome in which the pain is accompanied by loss of function and evidence of autonomic dysfunction. In the clinical setting, this diagnosis is usually associated with other anatomic and psychological diagnoses and may be associated with a variety of systemic illnesses and medicolegal factors. All components should be assessed before a treatment plan is established. Priorities should go to emergency care, acute injuries, and systemic illness, psychiatric problems, and chronic anatomic problems, in that order. Early, accurate diagnosis improves prognosis.