Cholesterol Levels

A cholesterol test is a blood test that measures the amount of cholesterol and triglycerides (a type of fat) in your blood. Cholesterol is a waxy, fat-like substance that's found in your blood and every cell of your body. Your body needs some cholesterol to make hormones, vitamin D, and substances that help you digest foods.

Your liver makes all the cholesterol your body needs and removes excess amounts. Cholesterol is also found in foods from animal sources, such as meat, egg yolks, poultry, and dairy products. Foods high in dietary fat can increase the cholesterol in your blood.

If there's too much cholesterol in your blood, your liver can't remove it all. There are two main types of cholesterol: LDL (low-density lipoprotein), or 'bad' cholesterol, and HDL (high-density lipoprotein), 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. This buildup of plaque is known as atherosclerosis. Over time, plaque can narrow your arteries or fully block them.

When this happens, parts of your body may not get enough blood: If the blood flow to your heart is blocked, it can cause a heart attack.; If the blood flow to your brain is blocked, it can cause a stroke.; If the blood flow to your arms or legs is blocked, it can cause peripheral artery disease.; Other names for a cholesterol test: Lipid profile, Lipid panel

Why this test is done

Your provider may order a cholesterol test as part of a routine exam. When and how often you should get a cholesterol test depends on your age, risk factors, and family history. The general recommendations are:

For people who are age 19 or younger:

• The first test should be between ages 9 to 11
• Children should have the test again every 5 years
• Some children may have this test starting at age 2 if there is a family history of high cholesterol, heart attack, or stroke

For people who are ages 20 to 65:

• Younger adults should have the test every 5 years
• Men ages 45 to 65 and women ages 55 to 65 should have it every 1 to 2 years

For people older than 65:

• They should be tested every year

You may also have a cholesterol test more often if you are at high risk of heart problems because of:

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

How to prepare

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.

Sample type

Blood