Hemorrhagic Strokes

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Hemorrhagic strokes account for the remaining 20 percent of all strokes. They occur when weakened blood vessels within the brain rupture and bleed into the surrounding tissue. The escaped blood can compress or pinch nearby blood vessels, cutting off blood flow and depriving the surrounding tissue of oxygen. Though hemorrhagic strokes occur less frequently than ischemic strokes, they tend to affect larger areas of the brain. Symptoms of a hemorrhagic stroke may be more sudden and more severe, and these strokes carry a greater risk of death than ischemic strokes.

Hemorrhagic strokes can result from an aneurysm, which develops when the wall of a blood vessel weakens and thins, ballooning outward. If left untreated, the aneurysm continues to expand and weaken, increasing the likelihood of rupture. Hemorrhagic strokes can also result from an arteriovenous malformation (AVM), a cluster of enlarged, structurally weak blood vessels that forms during fetal development or possibly at birth. These malformed blood vessels are susceptible to rupture from the normal forces exerted by the flowing blood.

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