Atherosclerosis is the build up of a waxy plaque on the inside of blood vessels that affects only the inner lining of an artery and is characterized by plaque deposits that block the flow of blood. It is often called arteriosclerosis. Atherosclerosis, a progressive process responsible for most heart disease, is a type of arteriosclerosis or hardening of the arteries.
Plaque is made of fatty substances, cholesterol, waste products from the cells, calcium, and fibrin, a stringy material that helps blood to clot. As the inner layer of the artery wall thickens, the artery's diameter is reduced, andblood flow and oxygen delivery are decreased. Plaques can rupture or crack open, causing the sudden formation of a blood clot (thrombosis). Atherosclerosis can cause a heart attack if it completely blocks the blood flow in the heart (coronary) arteries. It can cause a stroke if it completely blocks the brain (carotid) arteries. Atherosclerosis can also occur in the arteries of theneck, kidneys, thighs, and arms, causing kidney failure or gangrene that leads to amputation.
Atherosclerosis can begin in the late teens, but it usually takes decades tocause symptoms. Some people experience rapidly progressing atherosclerosis during their thirties, others during their fifties or sixties. Atherosclerosisis complex. Its exact cause is still unknown, however a person who has high cholesterol, high blood pressure, and smokes cigarettes is eight times more likely to develop atherosclerosis than someone who does not have these risk factors. Physical inactivity, diabetes, and obesity also increase the risk of atherosclerosis. Many of these risk factors can be eliminated by lifestyle changes.
Some risk factors cannot be changed. These include heredity, age, gender, andethnicity. People whose parents have coronary artery disease, atherosclerosis, or stroke at an early age are at increased risk. The high rate of severe hypertension among African-Americans puts them at increased risk. Risk is higher in men who are 45 years of age and older and women who are 55 years of ageand older.
Symptoms differ depending upon the location of the atherosclerosis, but include chest pain, heart attack, or sudden death, dizziness, weakness, loss of speech, blindness, disease of the blood vessels in the outer parts of the body(peripheral vascular disease), and high blood pressure that is difficult to treat.
Physicians may be able to diagnose atherosclerosis during a physical exam bymeans of a stethoscope and gentle probing of the arteries with the hand (palpation). More definite tests are electrocardiography, echocardiography or ultrasonography of the arteries, radionuclide scans, and angiography. Coronary angiography is the most accurate diagnostic method and the only one that requires entering the body (invasive procedure).
Treatment for atherosclerosis includes lifestyle changes, lipid-lowering drugs, coronary angioplasty (a non-surgical procedure in which a catheter tippedwith a balloon is threaded from a blood vessel in the thigh into the blockedartery), and coronary artery bypass surgery. Atherosclerosis requires lifelong care.
Patients who have less severe atherosclerosis may achieve adequate control through lifestyle changes and drug therapy. Many of the lifestyle changes helpprevent the disease and promote good health. Most of the drugs prescribed foratherosclerosis seek to lower cholesterol. Alternative therapies that focuson diet and lifestyle can help prevent, retard, or reverse atherosclerosis. These include some herbal therapies, relaxation techniques, and dietary modifications.
Atherosclerosis can be successfully treated but not cured. Recent clinical studies have shown that atherosclerosis can be delayed, stopped, and even reversed by aggressively lowering cholesterol. New diagnostic techniques enable physicians to identify and treat atherosclerosis in its earliest stages. New technologies and surgical procedures have extended the lives of many patients who would otherwise have died.