Normal adult serum cholesterol levels are less than 5.20 mmol/L, more than 5.20 mmol/L but less than 6.20 mmol/L is considered borderline, and more than 6.20 mmol/L is considered elevated, and can be seen as a result of a variety of physiologic or disease factors. Serum cholesterol is an important component of lipids, consisting of cholesteryl esters and free cholesterol. Pathologic causes of elevated blood cholesterol include cholestasis, hyperlipidemia, hypothyroidism, nephrotic syndrome, and hereditary factors. Physiological factors include smoking, alcohol consumption and mental stress. Pathological factors are recommended to go to the hospital in time for treatment; physiological factors such as smoking and drinking are recommended to quit smoking and drinking, eat a light diet, and review after a period of time. For abnormal cholesterol levels, timely consultation is recommended; for atherosclerosis and after treatment with lipid-lowering drugs, cholesterol and other lipid levels are also recommended.