What is the most significant and preventable risk factor for stroke?

Hypertension, or high blood pressure, is widely recognized as the most significant and preventable risk factor for stroke. Elevated blood pressure can lead to damage of the blood vessels, increasing the likelihood of them becoming narrowed or blocked. This can result in an ischemic stroke when blood flow to a part of the brain is interrupted. Additionally, hypertension can cause blood vessels to rupture, leading to hemorrhagic stroke.

Controlling blood pressure through lifestyle modifications such as diet, exercise, and medication can substantially reduce the risk of stroke, making it a crucial area for prevention efforts. Other risk factors, while also important, do not present the same level of preventability with lifestyle changes as hypertension does.