The normal range for LDL at age 75 should be less than or equal to 3.4 mmol/L. The normal range for low-density lipoprotein (LDL) (this range applies at any age) is ≤3.4 mmol/L, with borderline levels of 3.4 to 4.1 mmol/L and elevated levels of >4.1 mmol/L. LDL is a risk factor for atherosclerosis and can be used for early identification of atherosclerosis risk and for monitoring the course of lipid-lowering drug therapy. Elevated LDL is mainly seen in patients with increased risk of coronary heart disease, hereditary hyperlipoproteinemia, hypothyroidism, and nephrotic syndrome. It is recommended that patients with LDL abnormalities go to the hospital in time, complete the relevant examinations under the guidance of a professional doctor, and take targeted therapeutic measures.