It is well established that excessive sympathetic activity, resulting in the development of cardiopulmonary complications, commonly occurs in patients who have suffered aneurysmal subarachnoid haemorrhage. Cardiac dysfunction and neurogenic pulmonary edema are life threatening conditions that have serious implications with regard to patient outcome. The purpose of this article is to familiarize the neuroscience practitioner with the effects of subarachnoid haemorrhage on the heart and lungs and to provide an update in terms of current medical and nursing management trends. It is vital that these patients receive aggressive therapy including definitive surgical treatment of the aneurysm, vigilant monitoring for cardiopulmonary complications and prompt medical and nursing intervention should they occur. A brief review of the anatomy and physiology of the sympathetic division of the autonomic nervous system will be presented. In addition, the theories that have been proposed to explain the underlying pathogenesis will be introduced. Medical and nursing management strategies will also be addressed.