Cholesterol is made by the body and is also present in food. Many parts of the body depend on cholesterol for their proper function. However, too much cholesterol can build up in places where it is harmful, such as arteries.
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 affect on your blood cholesterol level.
One place where cholesterol causes trouble is in the walls of blood vessels. Too much blood cholesterol can make the blood vessel brittle or can block the flow of blood. Having unusually high levels of cholesterol in the blood increases the risk of heart attacks and strokes.
Heart attacks are caused by blockages in the blood vessels, or arteries, that nourish the heart muscle. Strokes are caused by small blood vessels in the brain that become blocked or leak. Lowering blood cholesterol reduces the risk of having a heart attack or stroke.
Most blood cholesterol screenings give the total cholesterol level. Knowing this level is an important first step in determining your risk for heart disease or stroke. Blood cholesterol levels below 200 are desirable. In middle-aged adults, this is a good indication of a relatively low risk of coronary heart disease. Any blood cholesterol level of 200 or more increases the risk for heart disease. Levels between 200 and 239 are “borderline-high.” A high blood cholesterol level is 240 or more. High readings indicate that the person has more than twice the risk of heart disease compared to someone whose cholesterol is 200.
Adults over 20 years of age should have their blood cholesterol tested at least once every 5 years. It’s also important to know what your HDL or “good” cholesterol level is. HDL cholesterol actually helps clear away “bad” cholesterol from the blood vessels.
When assessing a person’s risk for heart disease or stroke, a healthcare provider will look at other factors, as well. For example, people who smoke or who have diabetes, high blood pressure or who have excess body fat are at greater risk. Blood cholesterol levels are also affected by age, sex, heredity, diet and exercise.
Treatment for high blood cholesterol starts first with adjusting one’s diet. The American Heart Association suggests that consumption of fat should be 30 percent or less of your total day’s calories. Less than 10 percent of those total calories should come from saturated fats. Saturated fat is high in cholesterol and includes animal fats and some oils. It is solid at room temperature. If changing your diet does not decrease your cholesterol to a safer level, you may require medication.
Revision date: June 14, 2011
Last revised: by Janet A. Staessen, MD, PhD