Liver fibrosis is a scar repair reaction after chronic liver injury caused by various etiologies, and is an early reversible stage of cirrhosis, which may progress to decompensated cirrhosis and various complications of end-stage liver disease if left untreated. The common causes of liver injury are as follows. 1, viral hepatitis B and C viral hepatitis is the most common cause of liver cirrhosis. In China, chronic hepatitis B is the most common. The persistence of the virus is the main cause of liver injury evolving into cirrhosis, and the genetic background and genetic polymorphisms of the host may also influence the antiviral immune response, injury and fibrosis occurrence. Overlapping infections of hepatitis B and C often accelerate the development of cirrhosis. 2, alcoholic hepatitis (ASH) In Europe and the United States, alcoholic cirrhosis caused by ASH accounts for about 50% to 90% of all cirrhosis, and in recent years there has been a rising trend in China. Daily intake of 50g of ethanol and continued for more than 10 years 8% to 15% can lead to cirrhosis. Alcohol can also accelerate the progression of cirrhosis in hepatitis B and C. The pathogenesis of ASH is mainly the oxidative stress and lipid peroxidation damage to the liver caused by acetaldehyde, an intermediate metabolite of alcohol, which induces disorders of liver glucose and lipid metabolism and promotes inflammatory immune response and fibrosis. 3, non-alcoholic steatohepatitis (NASH) Usually refers to primary NASH associated with metabolic syndrome (including abnormalities such as abdominal obesity, fatty liver, type II diabetes, hyperlipidemia and hypertension.) With the advance of urbanization, lifestyle changes and the increase of high-fat and high-calorie diets, NASH has increased in both eastern and western countries. Approximately more than 1/3 of NASH patients may have fibrosis progression due to persistent liver injury. Steatosis of hepatocytes from various causes increases the susceptibility of the liver to inflammatory responses and various injury factors, which is the main mechanism of NASH pathogenesis. 4. toxins and drugs The liver is the main site of drug clearance, biotransformation and secretion. When the rate of production of toxic products during drug metabolism exceeds the rate of safe excretion it can cause liver injury. Thousands of drugs have been found to cause liver injury, including medically prescribed drugs and over-the-counter drugs and herbal medicines that people use for therapeutic, nutritional and other purposes. The vast majority of drug-related liver injury is atopic and unpredictable, and may be related to environmental and genetic susceptibility factors. Long-term use of certain drugs such as acetaminophen, methyldopa, flutamide or repeated exposure to certain chemical toxicants such as phosphorus, arsenic and carbon tetrachloride can cause toxic hepatitis, with the latter eventually evolving into cirrhosis. 5, autoimmune liver disease (AILD) AILD mainly includes autoimmune hepatitis (AIH) with hepatocyte involvement and primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) with bile duct cell involvement. AIH is mainly seen in women and is characterized by the presence of autoantibodies [such as antinuclear antibodies (ANA)] in the serum, increased serum transaminases and IgG levels, and massive plasma cell infiltration in the portal vein, and often responds to immunosuppressive agents such as hormones in treatment. PBC is a chronic progressive cholestatic liver disease that occurs mainly in middle-aged women between 40 and 60 years of age, and the majority of patients are positive for anti-mitochondrial antibodies (AMA.) PBC is often combined with other organ-specific autoimmune diseases such as scleroderma, autoimmune thyroid disease, and often with damage to salivary gland epithelial cells. PSC is a chronic cholestatic syndrome characterized by widespread inflammation and fibrosis of the intra- and extrahepatic biliary system with progressive development, mainly involving young people and 70% of patients are male. psc is often associated with inflammatory bowel disease and some specific complications such as cholangitis, biliary strictures, cholelithiasis, bile duct cancer, etc. The disease is often associated with inflammatory bowel disease and some specific complications such as cholangitis, bile duct stricture, cholelithiasis, bile duct cancer, etc. Inherited metabolic disease is a kind of liver disease caused by genetic and metabolic factors, mostly seen in adolescents. In China, congenital abnormalities of copper metabolism (hepatomegaly, i.e. Wilson disease) are most common. The disease is an autosomal recessive genetic disorder caused by abnormalities in the ATP7B gene, in which copper is deposited in the brain, liver and other tissues, with clinical symptoms of mental disorders, extrapyramidal symptoms and cirrhosis, accompanied by a decrease in plasma copper cyanogen and copper metabolism disorders. 7, hepatic stasis Chronic congestive heart failure, chronic constrictive pericarditis and obstruction of hepatic venous return caused by various etiologies, such as hepatic venous obstruction syndrome (Budd-Chiari syndrome) and hepatic small vein occlusive disease (VOD), can cause long-term stasis and hypoxia in the liver, fibrosis and sclerosis. 8.Other such as secondary cholestatic cirrhosis, which is mostly caused by cholelithiasis in adults, in addition to chronic inflammation or post-surgical stenosis of the biliary tract, peripotent cancer, bile duct cysts, congenital extrahepatic biliary atresia or intrahepatic bile duct development disorder. Schistosomiasis cirrhosis is caused by the deposition of eggs in the confluent area to stimulate fibrosis progression.