Lipids are the general term for the lipids contained in blood, mainly containing cholesterol, triglycerides, phospholipids, fatty acids, etc. They are normal components of blood. Because lipids are insoluble in water like the fats we usually see, they must be combined with a special type of protein in the blood to form a water-soluble complex called lipoprotein, such as low-density lipoprotein (LDL) and high-density lipoprotein (HDL). A large number of basic studies have shown that the development of coronary heart disease is very related to blood lipids, which is an independent and important risk factor for the occurrence of coronary heart disease. Due to dietary habits, cholesterol is the main cause of increased blood lipids in Westerners, while triglycerides are predominant in Asians. Excessive lipids in the blood, including cholesterol, triglycerides and LDL, the most important of which is LDL, will gradually remain on the walls of the arteries, which, over time, can thicken and harden the walls of the arteries and form atherosclerosis. If atherosclerosis occurs in the coronary arteries of the heart, it will cause blockage of the lumen of the blood vessels and thrombosis, so there will be insufficient blood supply, and a series of symptoms of coronary heart disease may occur. HDL, on the other hand, has a protective effect and can prevent the formation of atherosclerosis. Studies have shown that a 1% reduction in blood cholesterol concentration can reduce the incidence of coronary heart disease by 2%. At present, countries around the world have regarded high blood lipids as the number one killer of coronary heart disease, which means that high blood lipids are the main culprit of coronary heart disease.