HDL-C refers to high-density lipoprotein (HDL) cholesterol, and the normal range for men is 1.16~1.42 mmol/L; for women, the normal range is 1.29~1.55 mmol/L. HDL cholesterol is mainly synthesized in the liver and can fight against atherosclerosis. The higher the plasma level of HDL cholesterol, the lower the risk of cardiovascular disease, but it is not the higher the better. Generally adult men are at 1.16~1.42 mmol/L (45~55 mg/dl); women are at 1.29~1.55 mmol/L (50~60 mg/dl). Generally its ideal normal range is >1.04 mmol/L (>40 mg/dL), if it is ≥1.55 mmol/L (60 mg/dL) that is elevated, may be exercise, alcohol, taking contraceptives or cholesterol-lowering drugs, etc. caused by the increase, but also chronic liver disease, chronic toxicity and so on caused by the increase. If it is <0.91 mmol/L (<35 mg/dL) is lowered, it may be caused by coronary heart disease, hypertriglyceridemia, cirrhosis, diabetes mellitus, chronic renal insufficiency, malnutrition and so on. It is recommended to do more exercise in daily life, eat less high cholesterol food such as animal offal, and consult a doctor for examination in time if you feel unwell.