Normal results for a typical bilirubin test are 0.1 to 1 milligram per deciliter (mg/dL) of total bilirubin (direct plus indirect) and 0 to 0.3 mg/dL for direct. These results may vary slightly from laboratory to laboratory and are typical for adult men. Normal results may be slightly different for women and children, and results may be affected by certain foods, medications or strenuous exercise. Be sure to tell your doctor about any foods or medications you've taken and your activity levels so that your results can be interpreted correctly.

Lower than normal bilirubin levels are usually not a concern. Elevated levels may indicate liver damage or disease.

Higher than normal levels of direct bilirubin in your blood may indicate your liver isn't clearing bilirubin properly, for example, because of a blocked bile duct. Elevated levels of indirect bilirubin may indicate other problems. One common, and harmless, cause of elevated bilirubin is Gilbert's syndrome, a deficiency in an enzyme that helps break down bilirubin. Your doctor may order further tests to investigate your condition. Bilirubin test results also may be used to monitor the progression of certain conditions such as jaundice.

Oct. 13, 2012