Autonomic dysreflexia (AD) is a characteristic syndrome that occurs in spinal cord injury (SCI) patients with lesions above the sympathetic outflow at T6 and rarely in those with lesions below T10. Symptoms are initiated by noxious stimuli below the level of injury which result in massive sympathetic discharges from the isolated cord. These produce what may be called a sympathetic storm manifest by severe life threatening hypertension. Anesthesiologists and surgeons dealing with SCI patients must know how to recognize this syndrome, how to prevent its occurrence and how to manage it aggressively. Choice of anesthesia is frequently difficult and, in particular, it may be difficult to decide which type of anesthesia is best for patients susceptible to the syndrome. Therefore, we have conducted a retrospective study of SCI patients in the Department of Veterans Affairs Medical Center, Long Beach, California, where the Spinal Cord Injury Service is one of the largest in the country.