An LDL value of 4 mmol/L is on the high side, and a typical value should be ≤ 3.4 mmol/L. LDL is a class of cholesterol-rich lipoprotein, a complex of protein, cholesterol and phospholipids, and its high level may cause atherosclerosis, which is a risk factor that needs to be controlled in time. Generally, the level of LDL should be controlled below 3.4mmol/L, but patients suffering from some diseases should have their LDL level controlled even lower, for example, patients with existing atherosclerosis should have their value controlled below 2.6mmol/L, and patients suffering from cerebral infarction, heart attack and other cardio-cerebral vascular diseases need to keep it below 1.8mmol/L. The symptoms of high LDL alone cannot accurately determine the cause of the disease, but must be combined with the characteristics of the medical history and other test results to make an accurate judgment. People with LDL values up to 4mmol/L need to go to the hospital for diagnosis and consult a doctor to avoid further damage to the blood vessels that could lead to more serious diseases.