The HDL (High-Density Lipoprotein) Cholesterol test measures the level of HDL cholesterol in the blood, often referred to as "good cholesterol." HDL helps remove excess cholesterol from the bloodstream and transport it to the liver for excretion, protecting against heart disease.

Preparation: Fasting for 9-12 hours may be recommended, especially if the test is part of a full lipid profile, but it is not always necessary for just an HDL measurement. Follow any specific instructions from your healthcare provider.

Procedure: A blood sample is drawn from a vein, usually in the arm.