LDL is low-density lipoprotein, and LDL 5.5mmol/L is a high level, which requires oral statin drugs such as atorvastatin calcium tablets or cholesterol absorption inhibitors such as ezetimibe for lipid-lowering treatment. Statins can inhibit the synthesis of LDL in the liver, thus lowering the LDL level. Commonly used drugs include atorvastatin, resuvastatin, simvastatin and so on. Cholesterol absorption inhibitors can reduce intestinal absorption of cholesterol, thus reducing LDL levels, commonly used drugs are mainly ezetimibe. In addition to taking related medications, patients should eat a healthy diet and reduce the consumption of high-fat foods such as fried foods and animal offal. All of the above drugs are prescription drugs and need to be used under the guidance of a doctor.