It is also manufactured in the human body by the liver. You need small amounts of cholesterol to make and maintain nerve cells and to manufacture natural hormones. When you have too much cholesterol in your bloodstream it is called hypercholesterolemia, or high cholesterol. Hypercholesterolemia increases your risk of heart disease. The most common cause of high cholesterol is eating foods that are high in saturated fat or cholesterol.
Excess cholesterol causes deposits to form inside blood vessels.
These deposits, called plaque, are made of fats carried by the bloodstream. Atherosclerosis, a condition in which blood vessels become hardened and narrowed by the fatty deposits, may result. Atherosclerosis causes decreased blood flow. Blood clots may form in these narrowed vessels and totally stop blood flow. When this happens in the heart it causes a heart attack.