Most of the intra- and extra-hepatic dilatation refers to the dilatation of intrahepatic bile ducts, which may be caused by congenital factors, gallstones or tumors. 1. Congenital factors: For example, congenital choledocholithiasis causes dilatation of the bile ducts in the liver, which is a congenital biliary developmental abnormality. 2. Gallstones: Various types of gallstones may compress the bile ducts and cause bile discharge obstruction, resulting in intrahepatic bile duct dilatation. 3. Tumor: for example, tumor in the head of pancreas or neighboring organs, tumor of gallbladder itself may cause bile duct dilatation. There may be other reasons for intrahepatic bile duct dilatation, so you need to go to the hospital in time for further examination to clarify the cause of the disease, and carry out treatment according to the cause of the disease.