Carotid artery disease, or carotid artery stenosis, is the narrowing of the carotid arteries. This narrowing is usually caused by the buildup of fatty substances and cholesterol deposits, called plaque.

You have two common carotid arteries, one on each side of your neck. They each divide into internal and external carotid arteries. The internal carotid arteries supply oxygen-rich blood to your brain. The external carotid arteries supply oxygen-rich blood to your face, scalp, and neck.

Carotid artery disease (CAD) is a major cause of stroke in the United States. Over time, plaque hardens and narrows the arteries. This may limit the flow of oxygen-rich blood to your organs and other parts of your body (atherosclerosis).