Hyperlipidemia, as it is usually referred to, is a syndrome of systemic lipid metabolism abnormalities in which serum cholesterol (TC), triglycerides (TG) and/or low-density lipoprotein (LDL) are elevated and/or serum high-density lipoprotein (HDL) is too low. In normal individuals, lipids are in dynamic balance within a certain range: TC <5.2 mmol/L (200 mg/dl), LDL <3.4 mmol/L (130 mg/dl), TG <1.7 mmol/L (150 mg/dl); if TC ≥6.2 mmol/L (240 mg/dl), LDL >4.1 mmol/L ( 160mg/dl), HDL＜1.04mmol/L (40mg/dl), TG＞2.26mmol/L (200mg/dl) are called disorders of lipid metabolism. TC is an indispensable and important substance for the body, but too high can directly damage the arterial endothelium, causing the endothelial cells to swell and peel off. The lipids then invade the intima and middle layers of the arteries through the damaged areas. The accumulated lipids stimulate smooth muscle cells to proliferate and engulf the lipids, while macrophages in the blood also engulf the lipids in large quantities to form foam cells. If lipids are not effectively controlled, lipids and foam cells will continue to accumulate, smooth muscle cells will continue to proliferate, and collagen fibers and extracellular matrix will be synthesized in large quantities, resulting in the formation of atherosclerotic plaques, which will lead to coronary heart disease if they occur in coronary arteries. Recent studies have found that the risk of atherosclerosis is no less when HDL is low than when TC and TG are high. Unlike other lipid components, HDL is an important protective factor for cardiovascular disease. Hyperlipidemia is very common in China. According to the survey, 10%-20% of adults have elevated total serum TC or TG, and even nearly 10% of children have elevated lipids, and the incidence of hyperlipidemia has a tendency to rise gradually. Because patients often have lower HDL, “hyperlipidemia” is more appropriately called “dyslipidemia”.