Light micrograph section through human liver showing evidence of liver obstructive jaundice. When bile ducts become blocked, the bile builds up in the liver and jaundice (yellow colour of the skin) develop due to the increasing level of bilirubin in the blood. The possible causes of a blocked bile duct include: Cysts of the common bile duct and enlarged lymph nodes in the porta hepatis. A blockage such as this can also lead to bacteria backing up into the liver, which can cause a severe infection known as ascending cholangitis.