Heart disease comprises a number of various conditions. Arteriosclerosis is the hardening of the arteries - a number of minerals and fatty deposits collect and make the walls of the artery become rigid and hard. Atheriosclerosis is the most common condition and is caused by plaque - a buildup of fats, cholesterol and other substances. The more plaque that accumulates, the narrower the arteries become, which reduces the amount of blood that can make it to and from the heart. The heart must work harder to pump to maintain blood flow or, worse, may not be able to get blood to certain areas of the body at all. There are no real symptoms of atheriosclerosis beyond angina pectoris.