LDL cholesterol 3.97mmol/L is borderline elevated, not very serious, but more serious for those with high risk factors, but do not be too nervous, and actively cooperate with the diagnosis and treatment can be. The normal reference range of LDL cholesterol is less than or equal to 3.4mmol/L, 3.4～4.09mmol/L belongs to the marginal level, and more than 4.09mmol/L belongs to the elevated level, which is more serious. As long-term high levels increase the incidence of atherosclerotic diseases such as coronary heart disease and cerebral infarction, active intervention is needed. Especially for patients who already have risk factors such as coronary heart disease, hypertension, diabetes, etc., it is necessary to pay close attention to its level and try to control it to less than 1.8mmol/L or even lower. It is recommended to consult a doctor for standardized diagnosis and treatment when necessary.