For the normal human liver, its main functions are as follows: First, the liver has the function of secreting and excreting bile. After the liver secretes bile, it is discharged into the gallbladder through the fourth bile duct, the third bile duct, the second bile duct, the first bile duct, the left and right hepatic ducts, and the common hepatic duct, where it is concentrated and stored. After eating fatty foods or a high-protein diet, the concentrated bile is excreted from the gallbladder and discharged into the intestinal cavity through the common bile duct to emulsify fat. Secondly, the liver is also involved in the metabolism of sugars and related substances such as proteins and fats. Third, it synthesizes some of the prothrombin and some of the vitamins and other protein substances. Fourth, the liver also has some detoxification functions. Some of the drugs and most of the toxic substances taken are detoxified and metabolized by the liver, and then excreted out of the body through the bile and urine and other means. Therefore, for normal people, they should pay attention not to drink alcohol, not to stay up late, not to exert themselves, to maintain the body’s self-immunity, and to take appropriate supplements of various trace elements.