The purpose of review of systems is to elicit symptoms of occult disease and to determine the stability of current disease processes. Coexisting illnesses may complicate the surgical and anesthetic course. These illnesses should be evaluated in a systematic organ systems approach with an emphasis on recent changes in symptoms, signs, and treatment (see, also, Chapters 2 through 6). In certain circumstances, preoperative specialty consultation may be needed to answer specific questions about the interpretation of unusual laboratory tests, unfamiliar drug therapies, or changes in the patient's baseline status. Consultants should not be asked for a general “clearance” for anesthesia because this is the specific responsibility of the anesthesiologist. A minimum review of systems should seek to elicit the following information: