HDL is a beneficial serum protein, a protective protein, which is mainly synthesized in the liver and undertakes the role of transporting cholesterol. With low HDL, the body’s ability to adsorb blood lipids in blood vessels will be reduced, which will easily lead to hyperlipidemia, coronary heart disease, cerebrovascular disease and liver cirrhosis. I. Causes: 1, bad lifestyle: long-term intake of more high-fat food, a lot of alcohol and smoking, prolonged late night irregularities, lack of exercise may cause low HDL; 2, disease factors: clinically, hepatitis disease is the most common cause of low HDL. In addition, kidney failure, diabetes, nephrotic syndrome can also directly lead to low HDL. Treatment: People with low HDL, if they have cardiovascular system diseases, need medication to treat them, they can take oral statins such as pravastatin and atorvastatin to raise HDL. Interventions to increase HDL should be accompanied by lowering total cholesterol and LDL levels in order to effectively prevent disease progression. In addition, it is also necessary to regulate the lifestyle, pay attention to low salt and low fat diet, regular work and rest without staying up late, adhere to exercise and exercise, reduce weight in overweight and obese people, quit smoking and alcohol, and maintain a happy mood, which can also help to improve the low HDL situation.