Acute cholangitis is mainly caused by the complication of bacterial infection after different degrees of obstruction of bile ducts; chronic cholangitis is caused by the dysfunction of hepatocytes and capillary bile ducts. 1. Acute cholangitis: bile duct stones are the more common cause of acute cholangitis, and stone obstruction of the bile duct can cause inflammation. Bile duct injury or congenital malformation can lead to bile duct stenosis, stenosis causes bile stagnation in the bile duct, the bacteria entering the bile duct multiply, causing secondary biliary tract infection, leading to acute cholangitis. After bile-intestinal anastomosis and various cholangiography, the pressure in the bile duct is high after the operation, the wall of the bile duct is damaged, and the bacteria take advantage of the opportunity to multiply and cause cholangitis; the blockage or compression of the tumor can cause stenosis, and then the bacterial infection triggers inflammation. 2. Chronic cholangitis: acute cholangitis can be transformed into chronic cholangitis after repeated delay; intestinal bacteria can invade the biliary system, forming chronic inflammation and narrowing the wall of the bile ducts; in patients with autoimmune diseases, the immune complexes in the serum are higher than those in normal people, and chronic cholangitis can be caused by the deposition of these substances in the bile ducts. Patients with a confirmed diagnosis of cholangitis are advised to go to the hospital in a timely manner.