LDL 4.0mmol/L is at a borderline level and is not very serious, but still needs to be decided based on the clinical situation. The normal value of LDL is ≤3.4mmol/L, >4.1mmol/L is considered to be elevated, and 4.0mmol/L represents a borderline level, which needs to be considered in conjunction with the patient’s age, body type, whether there are diseases such as fatty liver and other conditions, liver function, lipid monitoring indexes, etc., to determine whether it is serious or not. If necessary, weight loss, diet control and other exercises and medication should be carried out under the guidance of a doctor. LDL can determine the risk of atherosclerosis, coronary heart disease, and cerebral infarction at an early stage, and monitoring of LDL is also required during the use of lipid-lowering drugs. It is recommended to consult a doctor as soon as possible if you find dyslipidemia or other discomforts to avoid delaying your condition.