Cholesterol is a sticky, fatty substance produced in the liver or obtained through dietary sources. Some cholesterol is important for hormone production, cell membrane health and Vitamin D synthesis. When cholesterol levels become excessive, however, there is an increased risk of heart disease and stroke. According to the National Heart, Lung and Blood Institute, heart disease is the leading cause of death in the United States, killing more than a half million men and women every year.
Atherosclerosis
When blood levels of cholesterol become too high, the excess cholesterol sticks to the walls of arteries, which are the blood vessels that carry blood away from the heart to other organs and parts of the body. This cholesterol build-up, called plaque, accumulates and narrows the arteries. When the arteries become severely narrowed, blood flow is restricted or blocked. This condition is called atherosclerosis, or the "hardening of the arteries." According to Discovery Health, plaque may accumulate inside the arteries for years before symptoms develop.
Coronary Heart Disease
Cholesterol also affects the coronary arteries that bring blood back to the heart. When these arteries become narrowed or blocked, blood flow to the heart decreases and the heart becomes deprived of oxygen. This condition, called coronary heart disease, causes angina and may lead to a heart attack.
Blood Clots
One potentially fatal danger of cholesterol is the risk of blood clots caused by the rupture or tearing of hardened coronary arteries. When tearing occurs, the body attempts to seal the tear by producing blood clots. Experts at the University of Maryland Medical Center state that these clots may completely obstruct blood flow and cause the heart to stop beating. If one of these clots travels to the brain, a stroke occurs.
