High-density lipoprotein and low-density lipoprotein are actually opposite lipoproteins. High-density lipoprotein has the effect of preventing the progression of atherosclerosis and can inhibit the progression of atherosclerosis, while low-density lipoprotein cholesterol is a lipoprotein that can cause atherosclerosis, so the two lipoproteins are fundamentally different. Some studies have shown that the correlation between the progression of atherosclerosis and LDL is the highest, so that is why in clinical practice, LDL should be lowered first and only when it is below the normal range is it qualified, HDL cholesterol is relatively speaking the higher the better the lipoprotein, while LDL cholesterol is the lower the better for patients with cardiovascular disease. The higher the HDL cholesterol the better the lipoprotein, while the lower the LDL cholesterol the better the lipoprotein for patients with cardiovascular disease.