Test Details: A serum bilirubin level greater than 2.5 to 3 mg per dL, in conjunction with yellow skin and sclera, is defined as jaundice. Bilirubin metabolism takes place in three phases—prehepatic, intrahepatic and posthepatic. Dysfunction in any of these phases may lead to jaundice. This test is done to identify the cause of health conditions like jaundice, anemia and liver disease.