Low-density lipoprotein is a type of lipoprotein in blood plasma. There are five types of lipoproteins in plasma, namely celiac particles, very low density lipoproteins, intermediate density lipoproteins, low density lipoproteins, and high density lipoproteins. The various lipoproteins decrease in size and increase in density gradually in that order. The main function of LDL is to transport cholesterol to extrahepatic tissues, which is an important lipoprotein leading to atherosclerosis. On the contrary, HDL transports cholesterol from peripheral tissues, including the arterial wall, back to the liver for metabolism and has an anti-atherosclerotic effect. Therefore, after elevated LDL cholesterol in blood, one should lower LDL cholesterol by changing life and diet habits and medication, with statin lipid-lowering drugs being preferred.