Carotid artery disease is a form of disease that affects the vessels leading to the head and brain. Like the heart, the brain’s cells need a constant supply of oxygen-rich blood. This blood supply is delivered to the brain by the two large arteries in the front of your neck. If these arteries become clogged or blocked, you can have a stroke. Carotid artery disease is usually caused by atherosclerosis, which is a hardening and narrowing of the arteries. As we age, fat deposits, cholesterol, calcium and other materials build up on the inner walls of the arteries. This build-up forms a wax-like substance called plaque. As the plaque builds up, the arteries become narrower, and the flow of blood through the arteries becomes slower. Lifestyle changes, medicines or surgery can be used to treat carotid artery disease and lower your risk of a stroke.