Total serum cholesterol is one of the most important indicators of lipid profile, which is the sum of cholesterol contained in lipoproteins in the blood. The normal reference range for total serum cholesterol is 3-5.69 mmol/L. Total cholesterol includes free cholesterol and total cholesterol esters. Studies have shown that long-term elevation of total cholesterol is the main cause of atherosclerosis, coronary heart disease, stroke and other cardiovascular diseases, so total cholesterol measurement has become an important test for lipid analysis in medical checkups. Clinical studies have confirmed that elevated cholesterol is clearly related to the formation of atherosclerosis and requires timely treatment with medication, and lowering cholesterol can reduce the incidence of coronary heart disease. Total cholesterol of 6.5 mmol/L is considered mildly elevated. Patients with total cholesterol of 6.5 mmol/L are recommended to take oral medication under the guidance of a physician to regulate the treatment. In daily life, patients should also pay attention to their diet, not to eat greasy food and high cholesterol food, it is recommended that patients should eat lightly, drink more plain water appropriately, and quit smoking and alcohol.