What Is It?
In a thrombotic stroke, a blood clot (thrombus) forms inside one of the brain's arteries. The clot blocks blood flow to a part of the brain. This causes brain cells in that area to stop functioning and die quickly.
The blood clot that triggers a thrombotic stroke usually forms inside an artery that already has been narrowed by atherosclerosis. This is a condition in which fatty deposits (plaques) build up inside blood vessels.