Atherosclerosis is the buildup of plaque in the arteries that may begin as early as childhood and continue progressively without outward symptoms. Plaque is mainly LDL cholesterol combined with other fatty substances, calcium, fibrin and cellular waste products. According to the Centers for Disease Control, the prevalence of atherosclerosis is 1 in 58 people in the U.S. or approximately 4.6 million adults. Atherosclerosis leads to cardiovascular diseases including strokes and heart attacks.
The Process of Plaque Buildup
A cross-section of normal arteries would show a hollow tube with a smooth and elastic lining called endothelium. As early as the adolescent years, streaks of fat from cholesterol begin to accumulate in the arterial walls. Fat buildup is progressive as a person ages although it is an asymptomatic process in the early stages.
Cholesterol buildup may damage the lining, triggering the release of chemicals to heal the endothelium but changing the surface as well. Other factors such as smoking, uncontrolled high blood pressure, diabetes and high cholesterol may also damage the endothelium. Low-density lipoprotein or LDL is considered bad cholesterol because it contributes to arterial plaque while high-density lipoproteins or HDL removes cholesterol from the arteries, transporting it to the liver where it is processed and broken down to substances that can be filtered out of the body.
As cholesterol plaque builds up, the lining surface becomes stickier, attracting even more substances circulating in the blood, including white blood cells. Plaque can accumulate inside the artery walls and away from the blood flow, or it can accumulate on the artery walls and grow slowly with minimal effect on blood flow for some time.
Typically, the structure of plaque deposits consists of a soft inner layer covered with a fibrous cap. When the covering is damaged, the fatty deposits are exposed prompting the formation of blood clots that may narrow the arteries even more.
Risks Associated with Cholesterol Buildup
Even when cholesterol plaques are stable, the person may experience some chest pain or angina. A sudden rupture that blocks blood flow to the heart leads to a heart attack or a myocardial infarction. Blocked blood flow to the brain may lead to a stroke while a clot that impedes blood flow to the arteries in the legs may cause peripheral arterial disease.
Plaque buildup in the artery walls is a complex process that involves several risk factors including diet, lifestyle choices, genetics and pre-existing conditions. Regular health screenings should address the possibility of atherosclerosis especially in middle age and older adults.