HDL

Alternate Names : High-Density Lipoprotein, Good Cholesterol

An HDL test measures the level of high-density lipoprotein, or HDL, in the blood. HDL is known as the good carrier for cholesterol. Cholesterol is a waxy substance that is used for many body processes. The HDL test is generally done along with a total cholesterol and LDL test.

The HDL test is usually done as part of a lipid profile test that also includes total cholesterol, LDL, and triglycerides.

Who is a candidate for the procedure?

An HDL test may be ordered to evaluate a person's risk for various conditions. Adults 20 years or over should be tested every five years for cholesterol, LDL, HDL, and triglycerides. Low HDL levels increase a person's risk for the following:

An HDL test may also be ordered to evaluate disorders of the kidney, liver, or thyroid gland.

How is the test performed?

A blood sample needs to be taken to measure the level of blood cholesterol. The blood is usually drawn from a vein in the forearm or the hand. First, the skin over the vein is cleaned with an antiseptic. Next, a strong rubber tube called a tourniquet is wrapped around the upper arm. This enlarges the veins in the lower arm by restricting blood flow through them. A very thin needle is gently inserted into a vein and the tourniquet is removed. Blood flows from the vein through the needle and is collected in a syringe or vial. The sample is sent to the lab to be analyzed. After the needle is withdrawn, the puncture site is covered for a short time to prevent bleeding.