The bile duct is a thin tube, about 4 to 5 inches long, that reaches from the liver to the small intestine. In the liver, it begins as many small channels that gather bile from the liver cells. These all join into one tube or duct (this part of the bile duct is called the hepatic duct). About one third of the way along the length of the bile duct, the gallbladder attaches by a small duct called the cystic duct. The combined duct is called the common bile duct.

The most common symptom of bile duct cancer is jaundice. Jaundice occurs when the liver cannot get rid of bile, and one of the chemicals in bile called bilirubin "backs up" into the bloodstream. Bilirubin is greenish yellow and colors all the body tissues, including the skin and the white part of the eyes, making people with this condition begin to look yellow. Because bilirubin also contributes to the brown coloring of bowel movements, the blockage of its flow into the intestine might lighten the color of one's stool. Bilirubin will also come out in the urine and turn it dark.

The top half of the bile duct is associated with the liver while the bottom half of the bile duct is associated the pancreas. The bile duct enters the part of the intestine called the duodenum into a structure called the Ampulla. Blockage of the bile duct causes build up of the bile in the blood since the bile can no longer go into the intestine. This condition is called jaundice and the skin becomes yellow from the accumulated bile in the blood.

Cancers of the bile duct are rare in the Western world. There are approximately 600 people diagnosed with cholangiocarcinomas each year in the UK. The bile ducts are the tubes connecting the liver and gall bladder to the small intestine (small bowel). Bile is a fluid made by the liver and stored in the gall bladder. Its main function is to break down fats during their digestion in the small bowel. In people who have had their gall bladder removed, bile flows directly into the small intestine. The bile ducts and gall bladder are known as the biliary system.

A fluid made by the liver to break down fats during digestion. The small ducts come together to form the right and left hepatic bile ducts, which lead out of the liver. The two ducts join outside the liver to become the common hepatic duct. The part of the common hepatic duct that is outside the liver is called the extrahepatic bile duct. The extrahepatic bile duct is joined by a duct from the gallbladder (which stores bile) to form the common bile duct. Bile is released from the gallbladder through the common bile duct into the small intestine when food is being digested.

A blocked bile duct can cause bile to accumulate in your gallbladder, making it larger than normal. Although your gallbladder is hidden behind other organs in your abdomen, your doctor can sometimes feel this enlargement during a physical exam or it may be detected on an ultrasound.

Jaundice (the skin turning yellow) and itching are the most common signs. Jaundice is caused by the accumulation in the skin of a component of bile (bilirubin) that normally empties into the intestines after traveling through the bile ducts.Bloating, weight loss, decreased appetite, fever, nausea or an enlarging abdominal mass are all signs that may be attributable to bile duct cancer. Pain usually signifies advanced disease.