Cholesterol and Triglycerides Tests

Test Overview

Cholesterol and triglyceride tests are blood tests that measure lipids—fats and fatty substances used as a source of energy by your body. Lipids are found in your blood and are stored in tissues. They are an important part of cells, and they help keep your body working normally. Lipids include cholesterol, triglycerides, high-density lipoprotein (HDL), and low-density lipoprotein (LDL).

Cholesterol and triglyceride tests measure:

• Total cholesterol level.
• Triglyceride level.
• HDL cholesterol level. This is the "good" cholesterol.
• LDL cholesterol level. This is the "bad" cholesterol.

Other measurements that may be done include:

• Apolipoprotein B (apoB) level.
• Lipoprotein (a) or Lp(a) level.
• Very-low-density lipoprotein (VLDL) cholesterol level.
• The ratio of total cholesterol to HDL.
• The ratio of LDL to HDL.

A ratio is how two cholesterol levels compare with each other. Higher ratios mean there's an increased risk of heart disease.

Your doctor may order these tests as part of a regular health exam. The results help your doctor check your risk of heart attack and stroke.

Follow your doctor's instructions on how to prepare for these tests. Not eating or drinking (fasting) before the blood test is not usually needed, but it may be recommended. Your doctor may ask you to fast except for drinking water for 8 hours before your test. In most cases, you can take your medicines with water the morning of the test. Do not drink alcohol for 24 hours before the test.

Why It Is Done

Cholesterol and triglyceride testing is done:

• As part of a routine physical exam to screen for high cholesterol and high triglycerides.
• To check if your levels are changing after taking medicine.
• If you have unusual symptoms, such as yellow fatty deposits (xanthomas) under the skin, near the eyes, or near joints. These symptoms may be caused by a genetic disease that causes very high cholesterol levels.

Your cholesterol levels can help your doctor find out your risk for having coronary artery disesase, heart attack, or stroke.

But it's not just about your cholesterol. Your doctor uses your cholesterol levels plus other things to find out your risk. These include:

• Your blood pressure.
• Whether or not you have diabetes.
• Your age, sex, and ancestry.
• Whether or not you smoke or vape.

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How To Prepare

• Not eating or drinking (fasting) before the blood test is not usually needed, but it may be recommended. Your doctor may ask you to fast except for drinking water for 8 hours before the test. In most cases, you can take medicines with water on the morning of the test.
• Do not drink alcohol for 24 hours before the test.
• Tell the doctor all the medicines, vitamins, supplements, and herbal remedies you take. Your doctor will tell you if you should stop taking any of them before the test and how soon to do it. Some of these may affect the results of this test.

How It Is Done

A health professional uses a needle to take a blood sample, usually from the arm.

Watch

How It Feels

When a blood sample is taken, you may feel nothing at all from the needle. Or you might feel a quick sting or pinch.

Risks

There is very little chance of having a problem from this test. When a blood sample is taken, a small bruise may form at the site.

Results

Results are usually available within 24 hours.

Ideal cholesterol and triglyceride numbers for adults

• Total cholesterol: Less than 150 milligrams per deciliter (mg/dL)
• HDL cholesterol: 60 mg/dL or higher is best (40 mg/dL or higher for men and 50 mg/dL or higher for women)
• LDL cholesterol: Less than 100 mg/dL (less than 70 mg/dL for people at high risk for a heart attack)
• Triglycerides: Less than 150 mg/dL

If your LDL cholesterol is 190 milligrams per deciliter (mg/dL) or more, it might mean that you have a familial lipid disorder.

For children and teens, test results are slightly different than for adults.