The metabolism of bilirubin is actually primarily in the hepatobiliary system, with an additional portion related to the blood system. So when you look at bilirubin, you also have to see urinary bilirubin. Total bilirubin comes from the hepatobiliary system, and part of it comes from the metabolism of red blood cells in the blood. For example, in hemolytic anemia, if there is hemolysis in the blood, the bilirubin level will also be elevated. For some liver and biliary diseases, such as when the bile ducts are blocked, bilirubin is also affected, but these two diseases actually do not have the same effect on the bilirubin concentration in the blood. In the case of bile duct blockage or because of biliary tract problems, high direct bilirubin in the blood is the main cause, while in the case of hemolysis, indirect bilirubin will be the main cause. When you get the labs, you have to assess whether the patient has cholestatic hepatitis or not, or whether there will be a separation of bile enzymes, i.e. transaminases and bilirubin going in different directions. If the transaminases are normal and the bilirubin is elevated, you actually have to focus on the biliary system. The blood system should also be checked, so it affects the total bilirubin, direct bilirubin, and indirect bilirubin may be divided into two parts, and the hepatobiliary as well as the blood system should be monitored.