Carotid artery disease seems to start when damage occurs to the inner layers of the carotid arteries. Major factors that contribute to damage include:
- High levels of certain fats and cholesterol in the blood
- High blood pressure
- High levels of sugar in the blood due to insulin resistance or diabetes
When damage occurs, your body starts a healing process. The healing may cause plaque to build up where the arteries are damaged.
The plaque in an artery can crack or rupture. If this happens, blood cell fragments called platelets will stick to the site of the injury and may clump together to form blood clots.
The buildup of plaque or blood clots can severely narrow or block the carotid arteries. This limits the flow of oxygen-rich blood to your brain, which can cause a stroke.