Patient education: Cholesterol tests (The Basics)

What is cholesterol? — Cholesterol is a substance in the blood known as a "lipid." Everyone has some cholesterol. It is needed for good health. But people sometimes have too much, which increases the risk of health problems.

What are cholesterol tests? — Different tests can be used to measure the amount of cholesterol in the blood.

The most commonly used test is called a "lipid panel." It measures the amount of several types of lipids, or fats, in your blood. Your doctor might also call it a "lipid profile."

A lipid panel can measure:

●LDL cholesterol – Some people call this the "bad" cholesterol. That's because having high LDL levels raises your risk of heart attack, stroke, and other health problems.

●HDL cholesterol – Some people call this the "good" cholesterol. That's because people with high HDL levels tend to have a lower risk of heart attack, stroke, and other health problems.

●Triglycerides – Triglycerides are not cholesterol, but they are another type of lipid. Having high triglycerides increases your risk of heart disease, stroke, and other health problems.

●VLDL cholesterol – This is another type of "bad" cholesterol that can be measured in a lipid panel. Having high VLDL levels can lead to plaque buildup in your arteries.

●Total cholesterol – This is the combined amount of all types of lipids in your blood. This includes LDL, HDL, triglycerides, and VLDL.

Sometimes, only the total cholesterol and HDL are measured.

Why might I get a cholesterol test? — Your doctor might want to check your cholesterol:

●As part of a routine check-up

●If you are at risk for heart problems – This could be because you have a family history of heart disease, or because you have certain health conditions like high blood pressure or diabetes.

●To see how well treatment is working, if you have already been diagnosed with high cholesterol or triglycerides

How do I prepare for a cholesterol test? — For this test, you need to get a "blood draw." Your doctor or nurse will tell you where to go for this. They will also give you instructions about eating or drinking before the test:

●If you are getting a lipid panel, they might tell you to avoid eating or drinking anything besides water for 8 to 12 hours before the test. You should also avoid alcohol for 24 hours before the test.

●If you are just getting a total cholesterol and HDL test, you do not need to avoid eating or drinking.

It might help to wear a short-sleeve shirt to your blood draw appointment. This makes it easier for the person drawing your blood to get to your arm.

What happens during a blood draw? — For the blood draw, a needle is used to take a small amount of blood from your arm (figure 1). Collecting the blood only takes a few minutes. The blood is then tested in a lab.

Tell the person who takes your blood:

●If you take "blood thinner" medicines or if you have a bleeding problem – They will make sure that your bleeding is under control before you leave.

●If you have a latex allergy – Some of the supplies used for blood draws might contain latex.

●If you have a preferred arm to use

Most of the time, getting blood taken does not cause problems. You might have a little soreness or bruising where the needle went in.

What do my results mean? — Your doctor or nurse will tell you when to expect your results, and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.

If your cholesterol test shows any abnormal results, your doctor or nurse will talk to you about what to do next. They might need to do more tests to figure out what the cause is.

If you do have a health problem, your doctor will work with you to come up with a plan for treatment.

More on this topic

Patient education: Triglyceride test (The Basics)
Patient education: High cholesterol (The Basics)
Patient education: High triglycerides (The Basics)

Patient education: High cholesterol and lipids (Beyond the Basics)