Integral to the successful rehabilitation of patients with myelopathies is the prompt and proper management of autonomic hyperreflexia. More than 80% of tetraplegic and high paraplegic patients experience this syndrome of disordered autonomic homeostasis during their rehabilitation. Successful prevention and management require a clear understanding of the pathophysiology, aided in particular by recent clarification of catecholamine activity in spinal man. Prevention is accomplished through optimal general medical care, as well as proper bladder, bowel and skin management. Treatment of the acute episode requires prompt identification and removal of the offending stimulus, and occasionally the administration of a potent direct vasodilator (diazoxide, nitroprusside). Recurrent episodes are approached through definitive management of the primary problem provoking the stimulus, accompanied by symptomatic prevention of the syndrome (mecamylamine, phenoxybenzamine).