High-density cholesterol generally refers to HDL cholesterol, which is mainly synthesized by the liver and consists of phospholipids, apolipoproteins, cholesterol and a small amount of fatty acids, and its main physiological function is to transport phospholipids and cholesterol. The physiological causes of low HDL cholesterol are common in obesity, smoking, long-term physical activity, stress, long-term alcohol consumption, etc. It is recommended to eat more fiber-rich foods, exercise properly, and prohibit smoking and alcohol. Low HDL cholesterol is one of the important risk factors of cardiovascular diseases. Cerebrovascular disease, coronary heart disease, hypertriglyceridemia, liver function damage, diabetes and other diseases can cause low HDL cholesterol. It is recommended to go to the hospital for examination in time and actively treat the primary disease to improve HDL cholesterol. Diet is recommended to consume a small amount of high cholesterol and high protein foods, low salt, low fat and low sugar diet, and you can eat cholesterol-lowering foods.