What do hdls do

10 thg 9, What does the test measure? An HDL cholesterol test analyzes a sample of blood to see how much cholesterol is present within high-density. Medically reviewed by Stacy Sampson, D.O. — Written by Jennifer Berry — Updated on HDL cholesterol helps remove LDL cholesterol from the blood and. What are the main roles of HDL cholesterol? HDL cholesterol has a protective role against diseases of the heart and blood vessels such as heart attacks and.