Bilirubin is a yellowish substance that is created by the breakdown (destruction) of hemoglobin, a major component of red blood cells.

Explanation of test results:

As red blood cells age, they are broken down naturally in the body. Bilirubin is released from the destroyed red blood cells and passed on to the liver. The liver releases the bilirubin in fluid called bile. If the liver is not functioning correctly, the bilirubin will not be properly released. Therefore, if the bilirubin level is higher than expected, it may mean that the liver is not functioning correctly.

Other things to know:

• Levels of bilirubin in the blood go up and down in patients with hepatitis C.
• When bilirubin levels remain high for prolonged periods, it usually means there is severe liver disease and possibly cirrhosis.
• High levels of bilirubin can cause jaundice (yellowing of the skin and eyes, darker urine, and lighter-colored bowel movements).
• Elevated bilirubin levels can be caused by reasons other than liver disease.