Cholesterol Levels

What is a Cholesterol Test?

A cholesterol test is a blood test that measures the amount of cholesterol and certain fats in your blood. Cholesterol is a waxy, fat-like substance that's found in your blood and every cell of your body. You need some cholesterol to keep your cells and organs healthy.

Your liver makes all the cholesterol your body needs. But you can also get cholesterol from the foods you eat, especially meat, eggs, poultry, and dairy products. Foods that are high in dietary fat can also make your liver produce more cholesterol.

There are two main types of cholesterol: low-density lipoprotein (LDL), or "bad" cholesterol, and high-density lipoprotein (HDL), or "good" cholesterol.

Too much LDL cholesterol in your blood increases your risk for coronary artery disease and other heart diseases. High LDL levels can cause the buildup of a sticky substance called plaque in your arteries. Over time, plaque can narrow your arteries or fully block them. When this happens, parts of your body don't get enough blood:

• If the blood flow to the heart is blocked, it can cause a heart attack.
• If the blood flow to the brain is blocked, it can cause a stroke.
• If the blood flow to the arms or legs is blocked, it can cause peripheral artery disease.

Other names for a cholesterol test: Lipid profile, Lipid panel

What is it used for?

A cholesterol test gives you and your health care provider important information about your risk of developing heart disease. If your test shows you have high cholesterol, you can take steps to lower it. This may decrease your risk of developing heart problems in the future. A cholesterol test measures:

• LDL levels. Also known as the "bad" cholesterol, LDL is the main source of blockages in the arteries.
• HDL levels. Considered the "good" cholesterol, HDL helps get rid of "bad" LDL cholesterol.
• Total cholesterol. The combined amount of LDL cholesterol and HDL cholesterol in your blood.
• Triglyceride levels. Triglycerides are a type of fat found in your blood. Some studies show that high levels of triglycerides may increase the risk of heart disease, especially in women.
• VLDL levels. Very low-density lipoprotein (VLDL) is another type of "bad" cholesterol. High VLDL levels have been linked to plaque buildup in the arteries. VLDL isn't usually included in routine cholesterol tests because it's difficult to measure. About half of VLDL is triglycerides, so your VLDL level can be estimated as a percentage of your triglyceride level.

Why do I need a cholesterol test?

Your provider may order a cholesterol test as part of a routine exam. You may also have a cholesterol test if you have a family history of heart disease or if your risk for heart problems is high because of:

• High blood pressure
• Type 2 diabetes
• Smoking
• Excess weight or obesity
• Lack of physical activity
• A diet high in saturated fat

Your age may also be a factor, because your risk for heart disease increases as you get older.

What happens during a cholesterol test?

A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

You may be able to use an at-home kit to check your cholesterol levels. Your kit will include a device to prick your finger to collect a drop of blood for testing. Be sure to follow the kit instructions carefully. Also, be sure to tell your provider if your at-home test shows that your total cholesterol level is higher than 200 mg/dl.

Will I need to do anything to prepare for the test?

You may need to fast (not eat or drink) for 9 to 12 hours before your blood cholesterol test. That's why the tests are often done in the morning. Your provider will let you know if you need to fast and if there are any other special instructions.

Are there any risks to the test?

There is very little risk to having a blood test. You may experience slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

What do the results mean?

Cholesterol is usually measured in milligrams (mg) of cholesterol per deciliter (dL) of blood. The information below will help you understand what your test results mean. In general, low LDL levels and high HDL cholesterol levels are good for heart health.

The LDL listed on your results may say "calculated." This means that your LDL level is an estimate based on your total cholesterol, HDL, and triglycerides. Your LDL level may also be measured "directly" from your blood sample. Either way, you want your LDL number to be low.

A healthy cholesterol level for you may depend on your age, family history, lifestyle, and other risk factors for heart disease, such as high triglyceride levels. Your provider can explain what's right for you.

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about my cholesterol levels?

High cholesterol can lead to heart disease, the number one cause of death in the United States. You can't change some risk factors for high cholesterol, such as age and your genes. But there are actions you can take to lower your LDL levels and reduce your risk, including:

• Eating a healthy diet. Reducing or avoiding foods high in saturated fat and cholesterol can help reduce the cholesterol levels in your blood.
• Losing weight. Being overweight can increase your cholesterol and risk for heart disease.
• Staying active. Regular exercise may help lower your LDL (bad) cholesterol levels and raise your HDL (good) cholesterol levels. It may also help you lose weight.

Talk to your provider before making any major change in your diet or exercise routine.