What can cause subarachnoid hemorrhage?

Subarachnoid hemorrhage refers to bleeding into the space surrounding the brain, and it can arise from several key causes. The options presented here highlight different potential contributors to this condition.

Focusing on the correct answer, arteriovenous malformations (AVMs), trauma, and Berry aneurysms are well-documented causes of subarachnoid hemorrhage. AVMs are abnormal connections between arteries and veins that can rupture and lead to bleeding. Trauma, such as head injuries, can also result in subarachnoid bleeding. Berry aneurysms, which are small, saccular outpouchings on cerebral arteries, are particularly significant in this context. When these aneurysms rupture, they can cause significant hemorrhage into the subarachnoid space, often leading to severe clinical consequences.

The other options do have relevance in different contexts but are less direct causes of subarachnoid hemorrhage. Hypertension and smoking are risk factors that can contribute to the likelihood of vascular events but are not direct causes of hemorrhage in this location. Clotting disorders typically lead to bleeding issues in different areas, while bacterial infections are more commonly associated with different types of meningeal inflammation rather than causing hemorrhage.