Cholesterol, a waxy substance found in fat cells in the blood, has useful purposes in the body. But when cholesterol levels rise too high, cholesterol may stick to the arteries, narrowing the interior of the blood vessel and making it harder for blood to pass. Decreased blood flow through the arteries to other parts of the body can cause a number of health problems.
Atherosclerosis
The buildup of plaque, which contains cholesterol, cellular debris, calcium and other substances, on the interior walls of blood vessels is called atherosclerosis. Atherosclerosis starts early in life and progresses over time. Atherosclerosis starts when the walls of blood vessels become damaged, which allows plaque to stick to them. Elevated cholesterol levels can both damage the walls and also contribute to plaque buildup. Low-density lipoprotein, or LDL cholesterol, causes more damage than high-density lipoprotein, or HDL cholesterol. The danger of atherosclerosis is that it can not only block blood flow through the vessel, possibly decreasing blood flow to the heart or lower extremities, but can also break off and travel to other parts of the body, such as the brain, causing a stroke.
Heart Disease
High cholesterol levels lead to reduced arterial blood flow in many cases. Reduced blood flow to the heart from plaque buildup in the arteries can cause coronary artery disease, blockages in the blood vessels that supply blood to the heart. Coronary artery or heart disease, the most common type of heart disease in adults, according to the National Heart Lung and Blood Institute, often causes angina, chest pain that worsens with exertion and improves when a person rests. If part of the plaque ruptures, blood clot formation at the site can completely block the artery, leading to a heart attack, the Mayo Clinic warns.
Stroke
If plaque breaks off and travels through the blood vessels to the brain, it can lodge in a blood vessel, cutting off blood supply to part of the brain. Plaque buildup in an artery leading to the brain can also block blood flow. Strokes caused by blood vessel blockage, called ischemic strokes, account for 86 percent of all strokes, the National Stroke Association reports. Stroke is the third-highest cause of death in the United States and the leading cause of adult disability, the same source notes. Strokes cause sudden onset of confusion, weakness on one side of the body, trouble talking or seeing, difficulty walking or severe headache. Transient ischemic attacks, also called TIAs, can serve as warning signs of possible problems within the blood vessels, since 40 percent of people who experience TIAs will later have a stroke, the National Stroke Association warns.
