
Normally our arteries are smooth and clean on the inside, but as you age, plaque can build up in the walls of your arteries. The plaque build-up restricts/reduces the blood flow in the carotid arteries. Sometimes the plaque deposits are soft and can crack or form rough areas inside the artery, causing a blood clot to form in your carotid artery. If the clot is large enough it can reduce or eliminate the blood flow to your brain and cause a stroke. Other times some of the plaque breaks away from the artery wall and travels through the bloodstream, lodging in a smaller artery in the brain and causing a stroke.
Carotid artery disease is a serious health problem because it can cause a stroke. Stroke is the third leading cause of death among adults in the US and is the leading cause of disability.