Low HDL cholesterol is not good. Serum HDL cholesterol is a type of lipoprotein with anti-atherosclerotic effects and is negatively correlated with the risk of developing cardiovascular disease, HDL cholesterol is a protective factor against cardiovascular disease. HDL is a good cholesterol that transports cholesterol, promotes cholesterol metabolism, stimulates prostacyclin production, reduces platelet aggregation, and inhibits oxidation of LDL. If HDL cholesterol is low, it indicates the presence of elevated blood lipids. Dyslipidemia may affect the metabolism of nutrients in the body, leading to atherosclerosis, which increases the probability of hypertension, coronary heart disease, and stroke. Therefore, when the HDL cholesterol is low, you should pay attention to low-salt and low-fat diet, eat more green vegetables and fruits, pay attention to strengthening exercise, reduce weight and waist circumference, and use lipid-lowering drugs under the guidance of a doctor if necessary.