Usually a cholesterol test is done after a person has not eaten for several hours, often overnight. A simple blood draw is taken and tested. Blood cholesterol levels below 200 in middle-aged adults appear to be a good indication of a relatively low risk of coronary heart disease. Unless your level is high, you do not need to repeat this test very often. Adults over 20 years of age should have their blood cholesterol tested at least once every five years.
Cholesterol is made by the body and is also present in food.
Many parts of the body, such as the brain and the adrenal glands, depend on cholesterol for their proper function. However, cholesterol in excess can build up in places where it is harmful. Hereditary factors and too much saturated fat in the diet can cause harmful effects. It is the saturated fat in food that has the greatest effect on your blood cholesterol level. One place where cholesterol causes trouble is in the walls of blood vessels.