LDL Cholesterol is the "bad" cholesterol that can lead to clogged arteries, heart disease, and stroke. Low-density lipoprotein carries cholesterol from the liver to cells throughout the body. What is LDL cholesterol and what does it do? Find out about the functions of this type of cholesterol and how to reduce LDL levels. Learn about the different types of cholesterol and what you can do to help manage your cholesterol.