Bilirubin is the brownish yellow substance found in bile. When the liver breaks down old red blood cells, it produces bilirubin. It is normally removed from the body through stool (feces). This soluble form is called direct (or conjugated) bilirubin. A blood test can be used to measure the levels of total and direct bilirubin. An insoluble form is called indirect (or unconjugated); it is not produced by the liver but passes through it.
The skin and the white of the eyes will have a yellowish tinge when bilirubin levels are high. This is called jaundice. There are a few illnesses that can cause jaundice: hepatitis, hemolytic anemia, or a blockage of the tubes that allow bile to pass from the liver to the small intestines. New born babies can be born with jaundice. These are a few reasons why a doctor may check bilirubin:
Some medications can cause bilirubin levels to rise. Low levels, on the other hand, can be caused from different medications.
Your bilirubin test levels can be affected by caffeine and fasting. When you have your test you need to make sure you don’t have any caffeine and that you do not fast. Also, you need to tell your doctor what medicines you are taking so that he/she can take this into account. Once the levels of bilirubin are restored to normal, (if jaundiced) the skin and the whites of the eyes will return to normal.