1) High density lipoprotein (HDL) is called good cholesterol because it removes cholesterol from the body and gets rid of it in the liver.2) High density lipoprotein (HDL) is called good cholesterol because it increases the oxygen content in the arteries and reduces the amount of plaque buildup.3) High density lipoprotein (HDL) decreases the bad cholesterol (low density lipoprotein \[LDL\]), and promotes excretion of it through the kidneys.4) High density lipoprotein (HDL) decreases low density lipoprotein (LDL) and prevents it from converting to very low density lipoprotein (VDRL), which is the worst kind of cholesterol in the body.