Arteriosclerosis is a hardening of the large and medium-sized arteries. The most common form of arteriosclerosis is atherosclerosis which is a hardening of the artery due to accumulation of atheromatous plaque. The plaque consists of cholesterol and lead to calcification and ulcers in the artery. Arteriosclerosis is different from arteriolosclerosis which is the hardening of smaller arteries.