USF-COM Department of Family Medicine

Patient Education Information on... Index of Patient Education Topics

What is Cholesterol?

Cholesterol is a waxy, fat-like substance found in every cell of the body.  It is used to help digest fats, strengthen cell membranes and make hormones.  Although cholesterol serves many important functions in the body, too much cholesterol in the blood can be dangerous.  That’s because excess cholesterol can clog coronary (heart) arteries, making it hard for blood to bring in oxygen and nutrients.  And if an artery becomes completely blocked, blood flow stops and a heart attack may occur.  Over half of all American adults have cholesterol levels that are too high.

The bloodstream transports cholesterol throughout the body by special carriers called lipoproteins.  The two major lipopro-teins are low density lipoproteins (LDL) and high density lipoproteins (HDL).

LDL - The "BAD" Cholesterol - LDL is the major cholesterol carrier found in the blood.  It carries cholesterol to the tissues of the body including the arteries.  LDL combines with other substances and sticks to the walls of arteries, forming plague.  Thus, a high level of LDL cholesterol increases your risk of heart disease.

HDL - The "GOOD" Cholesterol - HDL contains relatively small amount of cholesterol itself and carries away harmful fatty deposits from cells and tissues to the liver for excretion from the body.  This helps to prevent the buildup of cholesterol in the walls of your arteries.  If your level of HDL cholesterol is too low, your risk of heart disease actually increases.

Return to top of page


Do I have high cholesterol?

A simple blood test will screen for your levels of cholesterol.  It will tell you how much LDL, HDL, and total cholesterol you have in your blood.

In general, you should start having your cholesterol level checked at least once every five years starting when you are about 20 years old.  Children as young as two years old may need to have their cholesterol checked if a close relative, such as parent or grandparent, had heart disease before age 55, or if a close relative has high cholesterol.  Talk to your family doctor about how often you need to be tested.

Return to top of page


What do my test results mean?

Ideally, your total blood cholesterol level should be below 200.  Levels of 200 to 239 are considered "borderline," while levels above 240 are considered "high," meaning you have an increase risk of heart disease.

HDL and LDL are also important.  If your total cholesterol level is high because of a high LDL level, you may have a higher risk for heart disease or stroke.  If your total level is high only because of a high HDL level, you probably do not have an increased risk of heart disease.

An LDL cholesterol level of less that 130 is desirable.  An LDL level of 160 or higher means you have an increased risk for heart disease.  An HDL cholesterol level of less than 35 puts you at higher risk for heart disease, while an HDL level of 60 or above reduces your risk.

Return to top of page


How can I improve my LDL cholesterol level?

Follow a low fat, low cholesterol diet.  The American Heart Association recommends that no more than 30% of your total calorie intake be from fat.  Here are some tips on eating smart: Return to top of page

How do I improve my HDL cholesterol?

Your best bet for keeping your levels of both LDL and HDL cholesterol balanced is to develop a life-style that includes both a low fat diet and an ongoing exercise program that you enjoy.

Return to top of page


What if changing my diet and exercising isn’t enough?

If eating healthy, exercising and making other life changes, such as stopping smoking, do not adequately control your cholesterol levels after about 6 months, your doctor may want to discuss using medicine to lower your cholesterol level.  If so, please follow all instructions and continue to stick with your diet and exercise plan.  Weight loss and exercise will often lower your LDL cholesterol enough that you may be taken off medication.  This is important because, as with all medications, certain side effects may occur.

Return to top of page


Putting it all together.

Besides high cholesterol, there are other conditions or behaviors, called "risk factors," that are strongly related to an increased incidence of heart disease.  Your doctor looks at all your risk factors to decide what you need to do to lower your blood cholesterol and reduce your risk of heart disease.

Take this simple test and ask your doctor to help determine your risk of heart disease.
Did your father, brother, or son have a heart attack before the age of 55 or mother, sister, or daughter before the age of 65? 
Yes
No
Are you a man age > 45
Yes
No
Are you a woman age 55 or older,
or past menopause? 
Yes
No
Have you ever been told by your doctor that your HDL cholesterol was too low?
Yes
No
Have you ever been told by your doctor that you had high blood pressure?
Yes
No
Do you smoke cigarettes? 
Yes
No
Do you have diabetes? 
Yes
No
If you answer "YES" to any question, it means that you have that risk factor.
 
Your total number of "YES" answers and risk factors 

This information provides a general overview on lowering cholesterol levels and may not apply to everyone.  To find out if this information applies to you and to get fore information on this subject, talk to your family doctor.