This document provides information about jaundice and obstruction of the biliary tract. It begins with an overview of the causes of yellow discoloration of the skin and mucous membranes, which is caused by bilirubin accumulation. It then describes the breakdown of red blood cells and how bilirubin is processed and excreted. The document outlines various causes of obstructive jaundice including gallstones, strictures, tumors, and external compression. Investigation methods and treatment approaches for different biliary obstructions are also summarized.