LDL 4.1 usually refers to LDL cholesterol of 4.1 mmol/L, which is a borderline elevation, not considered serious, but should be actively intervened to reduce its harmful effects. LDL cholesterol is a cholesterol-rich lipoprotein, and contrary to HDL, it can be chemically modified and then ingested by phagocytes, forming foam cells and staying in the blood vessel wall, which can easily lead to a large amount of cholesterol deposition in the blood vessel, thus contributing to the formation of atherosclerotic plaques in the arterial wall, and thus it is one of the risk factors for atherosclerosis. Generally, the appropriate level of LDL cholesterol is <3.4 mmol/L, with a borderline level of 3.4-4.1 mmol/L, and when it is ≥4.1 mmol/L, it is elevated. When LDL cholesterol appears elevated, it should be taken seriously and intervention should be actively pursued. If the patient does not have other risk factors such as coronary heart disease or hypertension, dietary modification, increased exercise, and treatment through lifestyle changes can be prioritized. If it fails to decline or is accompanied by other risk factors, it should be treated with lipid-lowering drugs as prescribed by the doctor. In conclusion, LDL cholesterol of 4.1mmol/L is already elevated, but the elevation is not large enough to be considered serious, but if it is allowed to develop, it will progress to a serious stage and increase the risk of atherosclerotic cardiovascular disease.