LDL stands for low-density lipoprotein. It's also sometimes called "bad" cholesterol. Lipoproteins are made of fat and protein. They carry cholesterol, triglycerides, and other fats, called lipids, in the blood to various parts of the body.
This article discusses the blood test to measure the level of LDL cholesterol in your blood. Too much LDL in the blood can clog arteries.