What is often the cause of a subarachnoid hemorrhage?

A subarachnoid hemorrhage often occurs due to the rupture of an intracranial aneurysm. Intracranial aneurysms are weak spots in the walls of blood vessels in the brain that can balloon and fill with blood. When these aneurysms rupture, they release blood into the subarachnoid space, the area between the brain and the tissues that cover it, leading to a sudden and severe headache, often described as a "thunderclap" headache.

While arteriovenous malformations, severe head trauma, and systemic hypertension can also contribute to bleeding in the brain, they are less common causes of subarachnoid hemorrhage compared to the rupture of an aneurysm. Aneurysms are specifically noted for their potential to cause subarachnoid hemorrhage, making them a primary focus in understanding this condition. Recognizing ruptured aneurysms as the leading cause helps in proper diagnosis and swift treatment to mitigate the risks associated with this serious medical emergency.