There are three main typesTrusted Source of stroke: Ischemic stroke: This is the most common type of stroke, making up 87% of all cases. A blood clot prevents blood and oxygen from reaching an area of the brain. Hemorrhagic stroke: This occurs when a blood vessel ruptures. These are usually the result of aneurysms or arteriovenous malformations (AVMs). Transient ischemic attack (TIA): This occurs when blood flow to a part of the brain is inadequate for a brief period of time. Normal blood flow resumes after a short amount of time, and the symptoms resolve without treatment. Some people call this a ministroke.