what causes a stroke and a brain aneurysm?
Causes. A stroke occurs when the blood supply to your brain is interrupted or reduced. This deprives your brain of oxygen and nutrients, which can cause your brain cells to die. A stroke may be caused by a blocked artery (ischemic stroke) or the leaking or bursting of a blood vessel (hemorrhagic stroke).
1 High blood pressure. 2  The risk of subarachnoid hemorrhage is greater in people who have a history of high blood pressure. 3  Smoking. 4  In addition to being a cause of high blood pressure, the use of cigarettes may greatly increase the chances of a brain aneurysm rupturing.