What is the most common form of arteriosclerosis?

"atherosclerosis": "arteriosclerosis" refers to hardening of the arteries, of any cause. Far and away the most common form is due to "atherosclerosis"--build-up of plaque comprised of cholesterol, fat-filled white blood cells, and smooth muscle cells in the artery walls. The most common sites are heart (coronary arteries), brain (carotid arteries), and the arteries of the legs ("peripheral arterial disease" or pad).

Cholesterol build up: Arteriosclerosis is the process by which the artery wall hardens because of inflammation and cholesterol build up. The most common cause is high cholesterol levels.