What does the medical abbreviation HDL mean?

HDL(High-Density Lipoprotein) is the smallest of the lipoprotein particles. They are the densest because they contain the highest proportion of protein.HDL cholesterol, or "good" cholesterol, appears to scour the walls of blood vessels, cleaning out excess cholesterol. It then carries that excess cholesterol -- which otherwise might have been used to make the "plaques" that cause coronary artery disease -- back to the liver for processing. HDL cholesterol level helps fight heart disease.