A stroke occurs when blood flow to part of your brain suddenly stops. Your brain cells need oxygen and nutrients carried by the blood, so when a stroke happens, brain cells begin to die within minutes. Here is more information about different kinds of stroke and what causes them:
- Ischemic (say "iss-KEE-mick") stroke happens when a blood clot blocks a blood vessel in the brain. The clot may form in the blood vessel or travel from somewhere else in the blood system. About 8 out of 10 strokes are ischemic strokes. They are the most common type of stroke in older adults.
Hemorrhagic (say "heh-muh-RAW-jick") stroke develops when an artery in the brain leaks or bursts. This causes bleeding inside the brain or near the surface of the brain. Hemorrhagic strokes are less common but more deadly than ischemic strokes.
Transient Ischemic Attack (TIA), sometimes called a "mini-stroke" because the symptoms are like that of a stroke, but don't last long. A TIA happens when blood flow to part of the brain is blocked or reduced, often by a blood clot. After a short time, blood flows again and the symptoms go away. TIAs must be taken very seriously because they are indicators that you are likely to have a stroke soon.
Thrombotic stroke, also called cerebral thrombosis, occurs when a blot clot (thrombosis) forms inside an artery in the brain, blocking blood flow. Sometimes the clot forms in one of the arteries in the neck that transport blood to the brain.
Embolic stroke, also known as cerebral embolism, is caused by a blood clot. But unlike the thrombotic stroke, the clot originates somewhere other than the brain. Embolic stroke occurs when a piece of a blood clot breaks loose and travels in the blood stream in the brain. It travels until it reaches a point where it can go no farther and blocks up the vessel, cutting off the blood supply. The sudden blockage is called an embolism.
Brain Aneurysms and AVMs: A brain (cerebral) aneurysm is a bulging, weak area in the wall of an artery that supplies blood to the brain. In most cases, a brain aneurysm causes no symptoms and goes unnoticed. In rare cases the brain aneurysm ruptures, releasing blood into the skull and causing a stroke. A brain arteriovenous malformation (AVM) is a cluster of abnormal blood vessels in the brain that can burst and cause bleeding in the brain, leading to a stroke.
Learn more about stroke from Intermountain's Patient Education Library: