The assembly of fats, cholesterol and other substances found in the blood in and on the artery walls forms a plaque which obstructs normal blood flow. Atherosclerosis is a disease in which arterial cavity narrows due to the buildup of plaque. In severe cases, it can result in coronary artery disease, stroke, peripheral artery disease, or kidney problems, depending on which arteries are affected. When atherosclerosis becomes severe and causes irreversible ischemia, such as tissue loss in the case of peripheral artery disease, surgery may be preferred