What is ldl, what is hdl?

Bad and good: Ldl is the low density lipoprotein cholesterol, commonly known as the "bad" cholesterol as it is the one that increases ones risk for heart disease (through depositing plaque to the arteries.) HDL is the high density lipoprotein cholesterol, commonly known as the "good" cholesterol as it has cardio-protective effects when elevated.

Lipoproteins: Cholesterol and triglycerides are fats transported in the blood inside carrier vehicles called lipoprotein particles. Following entry into the artery wall low density lipoprotein (ldl) particles directly promote development of atherosclerosis ("hardening of the arteries") and increase risk for heart attack and stroke. High density lipoprotein (HDL) particles work in several ways to decrease ather.