The liver gets most of its blood supply from the intestine, so it is exposed to many pathogens, nutrients and metabolites from the intestine in the first place. It acts like a chemical factory to process these substances, delivering nutrients to the body, detoxifying harmful substances, and excreting them out of the body. The liver is an immune organ and there are many unique immune cells inside the liver. Therefore, it plays a very important role in the immune response of the body, especially in the natural immune response. If the immune microenvironment of the liver is imbalanced, it will lead to chronic inflammation of the liver, liver fibrosis and even liver cancer. So what are the common causes of chronic liver disease? 1. Chronic viral hepatitis, such as hepatitis B and C, can lead to liver fibrosis and cirrhosis. 2.Alcoholic liver disease, non-alcoholic fatty liver disease and drug-related liver disease will also become the most important chronic liver diseases in the future. 3. Other liver diseases (10%), i.e. liver diseases whose causes were previously unknown, were previously defined as “cryptogenic liver diseases”. 4. problems resulting in metabolic diseases of the liver. When the etiology of chronic liver diseases is clarified and then the proper treatment is given to the cause, their chronic inflammation can subside, fibrosis can even be reversed, and even early cirrhosis can be reversed, thus preventing the development of end-stage liver disease and liver cancer. Currently, infectious diseases (including viral liver disease) are very effectively controlled. Conversely, autoimmune diseases are on a steep rise. With regard to autoimmune liver disease, depending on the type of liver cells affected, we simply classify it into – autoimmune hepatitis, which is primarily directed at hepatocytes; primary biliary cholangitis, which is primarily directed at the small bile ducts, which we call interlobular bile ducts; and if both the bold ducts and small bile ducts are involved, we call primary sclerosing cholangitis. IgG4-related disease can also involve the biliary system and is called IgG4-related sclerosing cholangitis.