Subarachnoid Hemorrhage: Diagnosis and Acute Management

Bleeding in the subarachnoid space (subarachnoid hemorrhage/SAH) can be caused by a number of pathologies. Blood can enter the subarachnoid space from arterial lesions located within the subarachnoid space, from an intracerebral hemorrhage that extravasates into the subarachnoid space, from bleeding that arises in ventricles, or from ruptured vessels in the subdural space, which can cause bleeding that extends through the outer arachnoid layer.