Atherosclerosis comes from the Greek "athero," which means paste or gruel, and "sclerosis," which means hardness. Many experts believe that atherosclerosis starts with inflammation and damage to the innermost layer of the artery, known as the endothelium. As the endothelium becomes damaged and develops scar tissue, the fat and waste products in the blood combine with calcium to form plaques that bond with the scar tissue, usually in the large- and medium-size arteries.
Atherosclerosis can negatively affect the heart in several ways. First, the plaques can become brittle and rupture. This can cause blood clots to form, which can block blood flow or break off and travel to another part of the body. If either happens and blocks a blood vessel that feeds the heart, it causes a heart attack. If it blocks a blood vessel that feeds the brain, it causes a stroke. And if blood supply to the arms or legs is reduced, it can cause difficulty walking and eventually lead to gangrene.
Atherosclerosis can also cause the heart to work harder, to pump the blood through narrowing arteries. Lastly, the arteries, which are designed to expand and contract as needed, begin to stiffen and can no longer dilate when a part of the body needs more oxygen.
It's not possible to completely prevent atherosclerosis. It happens to everyone and likely begins in childhood. But the severity of atherosclerosis can be managed by taking steps to reduce cardiovascular disease.