subarachnoid hemorrhage
Pronunciation: suhb-uh-RAK-noid HEM-er-ij
Also written as: SAH — subarachnoid hemorrhage
Bleeding into the space between the brain and the thin tissues covering it, often caused by ruptured cerebral aneurysms.
Full Definition
Subarachnoid hemorrhage (SAH) is bleeding that occurs in the subarachnoid space, the area between the brain and the arachnoid membrane that surrounds it. This space normally contains cerebrospinal fluid, and bleeding here mixes with the CSF, often causing sudden severe headache described as 'the worst headache of my life.' The most common cause is rupture of a cerebral aneurysm, though trauma, arteriovenous malformations, and other vascular abnormalities can also cause SAH. The condition is a neurological emergency requiring immediate intervention, with complications including rebleeding, vasospasm, and hydrocephalus.
Usage
Usage note: Commonly abbreviated as SAH. Distinguish from other types of intracranial hemorrhage by anatomical location.
In Context
- "CT angiography confirmed subarachnoid hemorrhage with a ruptured anterior cerebral artery aneurysm." — radiology report
- "The patient developed delayed cerebral ischemia secondary to vasospasm following subarachnoid hemorrhage." — neurocritical care note