An HDL of 0.73 is considered decreased, but it should not be relied upon alone to indicate severity; a comprehensive assessment should be made in conjunction with the patient’s past history, such as the presence or absence of cardiovascular and diabetic diseases. The normal range of HDL is 1.04-1.55 mmol/L, which is an indicator of lipid metabolism and a predictor of coronary heart disease risk. HDL particles can send the cholesterol in the plaque back to the liver for degradation and can play an anti-atherosclerotic role. Therefore HDL cholesterol is also commonly known as the good cholesterol. Previous evidence-based medical evidence suggests that abnormal lipid metabolism is a key factor in the formation of atherosclerosis and that decreased HDL levels are an important risk factor for residual risk of coronary artery disease. Clinically, it is rare to see a decrease in HDL alone; it is often accompanied by other dyslipidemias and often requires combined lipid lowering. If you have a lowered HDL level, you should consult your doctor in the hospital, who will assess whether it is accompanied by other dyslipidemia and take lipid-lowering medication as soon as possible.