LDL Cholesterol Calc: LDL stands for Low-Density Lipoprotein, often called the “bad” cholesterol. LDL’s job is to carry cholesterol to your body’s tissues, but when levels are too high, it can build up in the walls of your arteries and form plaque. This buildup may increase the risk of heart disease and stroke. Lower LDL is generally better for protecting your heart and blood vessels. Higher LDL can mean more cholesterol is being deposited in the arteries.