What is the most common cause of subarachnoid hemorrhage (SAH)?

Subarachnoid hemorrhage (SAH) most commonly results from the rupture of an intracranial aneurysm, often referred to as a berry aneurysm, especially in non-traumatic cases. These aneurysms are small, saccular outpouchings that typically occur at the bifurcation of cerebral arteries. When they rupture, they can lead to sudden SAH, which is characterized by the rapid accumulation of blood in the subarachnoid space.

While trauma is indeed a significant cause of SAH, particularly in young individuals, it is not the most common cause in the general population. In cases without a clear history of trauma, the majority of SAH presentations are due to the rupture of an aneurysm, with berry aneurysms being the most prevalent among them.

Hypertension can contribute to the formation of aneurysms and may exacerbate bleeding, but it is not the direct cause of SAH. Although hypertension can cause small vessel disease and lead to other forms of hemorrhage, it does not account for the majority of SAH cases.

In summary, the most common cause of subarachnoid hemorrhage is indeed the rupture of an intracranial aneurysm, with berry aneurysms being the