High bilirubin test results may be indicative of blood disorders or impaired liver function, such as liver disease or blocked bile ducts. Too much bilirubin, or hyperbilirubinemia, in newborn babies can cause brain damage, according to WebMD.
Bilirubin is a brownish-yellow substance found in bile and is formed when the liver breaks down old red blood cells, explains WebMD. Due to its color, high bilirubin levels cause yellowing of the skin and whites of the eyes. This is known as jaundice. Bilirubin tests are used to derive three values of bilirubin levels: indirect, direct and total billirubin.
Higher-than-normal levels of direct or indirect bilirubin may indicate different types of liver problems, notes Mayo Clinic. Normal ranges for a bilirubin test are 0.1 to 1 milligram per deciliter of total bilirubin and 0 to 0.3 milligrams per deciliter for direct. These values vary slightly for women and children.
A bilirubin test is used to check if bile ducts are being blocked by tumors or gallstones; to check for signs of liver diseases, such as hepatitis or cirrhosis; or to diagnose blood diseases, such as hemolytic anemia, that cause increased destruction of red blood cells, states WebMD. It is also used to check if jaundice needs to be treated in newborn babies.