Blood lipids include total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides. Firstly, the symbol for total cholesterol is TC and the appropriate level should be less than 5.2mmol/L. Secondly, the symbol for LDL-C is LDL-C and the appropriate level is less than 3.4mmol/L. Secondly, the symbol for triglycerides is TG and the appropriate level should be less than 1.7mmol/L. Thirdly, the symbol for HDL-C is HDL-C. The higher this indicator is, the better it is, and if it is less than 1.0 mmol/L, it is called reduced HDL cholesterol. In actual clinical practice, especially in cardiology, the focus is on LDL cholesterol, and the higher the relative level, the more likely the patient is to develop atherosclerosis.