Aneurysmal subarachnoid hemorrhage (aSAH) is a neurological emergency with a high mortality rate in the acute period and a significant risk of mortality or permanent injury in the weeks following aneurysm rupture. In addition to neurologic injury, the systemic sequelae of aSAH impact multiple organ systems, confounding the treatment of vasospasm and delayed cerebral ischemia. Given the complexity of this disease process, aSAH patients should be cared for by multidisciplinary teams at high-volume centers in dedicated neurocritical care units. Although there is a paucity of high-quality evidence to guide management of aSAH, protocols that reflect the evolving risks these patients face in the hours, days, and weeks following aneurysm rupture can maximize the potential for neurologic recovery. This chapter is intended to provide an overview of these risks and serve as a guide for developing such protocols based on the best available evidence.