define ldl cholesterol
LDL cholesterol: Low-density lipoprotein cholesterol, commonly referred to as 'bad' cholesterol. Elevated LDL levels are associated with an increased risk of heart disease. Lipoproteins, which are combinations of fats (lipids) and proteins, are the form in which lipids are transported in the blood. Low-density lipoproteins transport cholesterol from the liver to the tissues of the body.