Primary sclerosing cholangitis (PSC) is a liver disease in which the bile ducts (small tubes through which bile flows from the liver to the gall bladder and intestines) progressively decrease in size due to inflammation and scarring. As a result, bile that is normally carried out of the liver accumulates within the liver, which then damages liver cells. The disease may sometimes be confined to the bile ducts within the liver but most often it also affects the large bile ducts outside the liver as well.
