The specialty of Pain Medicine is concerned with the prevention, evaluation, diagnosis, treatment, and rehabilitation of painful disorders. Such disorders may have pain and associated symptoms arising from a discrete cause, such as postoperative pain or pain associated with a malignancy, or may be syndromes in which pain constitutes the primary problem, such as neuropathic pains or headaches. The diagnosis of painful syndromes relies on interpretation of historical data; review of previous laboratory, imaging, and electrodiagnostic studies; behavioral, social, occupational and a vocational assessment; interview and examination by the pain specialist; and may require specialized diagnostic procedures, including central and peripheral neural blockade or monitored drug infusions. The special needs of the pediatric and geriatric populations are considered when formulating a comprehensive treatment plan for these patients.