When it comes to cholesterol, most people think of it as a “bad thing” in the human body. In fact, cholesterol is an essential substance for the human body and has many important functions. Today, we will talk about some knowledge of cholesterol. 1. In general, the lipid analysis carried out in hospitals includes triglycerides, total cholesterol, HDL cholesterol, LDL cholesterol, and in some cases, apolipoproteins. However, we should pay special attention to LDL cholesterol (medically referred to as LDL-C) because the higher the LDL-C, the higher the risk of cardiovascular adverse events such as heart attack and cerebral infarction; controlling LDL-C within the appropriate range can help prevent or reduce the occurrence of cardiovascular and cerebrovascular adverse events. 2. Cholesterol is a substance that exists in the human body. There are two main sources: one is synthesized in the body (mainly the liver), accounting for 70%-80%, and the other source is dietary intake, accounting for 20%-30%. It is an important substance for the composition of cell membranes, the synthesis of many hormones such as sex hormones, and the formation of bile acids. However, if the cholesterol in the body is too high, it will be easily deposited in the walls of arteries, forming atherosclerotic plaques, which will then develop into coronary heart disease and cerebrovascular disease. 3.How to lower cholesterol? To lower cholesterol levels, we have to start from two aspects, namely (1) reducing synthesis, mainly by taking statins such as atorvastatin, resorvastatin, simvastatin and so on. There are also ezetimibe and some other newer lipid-lowering drugs. (2) Reduce dietary intake and eat less cholesterol-rich foods such as animal offal, egg yolk, fish roe, etc.). (3) Treat the co-existing hyperglycemia, hypertension, obesity, etc. 4.After taking lipid-lowering drugs for a period of time, can I stop taking them if my cholesterol is normal? No! Cholesterol will rise again after stopping the medication, so it is necessary to adhere to the medication for a long time. In some patients, the dosage can be adjusted under the guidance of the doctor. 5.Is it reliable to say that blood exchange can lower cholesterol? The medical name for blood exchange is “plasma purification/replacement therapy”, and this treatment can indeed lower cholesterol. However, it is difficult to implement and is not recommended.