Bilirubin, Total

Total bilirubin is a blood test that measures the amount of bilirubin, a yellow pigment made when your body breaks down old red blood cells. The liver takes up bilirubin, changes it so it can be dissolved, and sends it into bile to leave the body through the intestines. Total bilirubin includes both forms in the blood, unconjugated and conjugated, which together reflect how your body is producing, processing, and clearing this pigment.

This test is often part of a liver panel. It helps show how well your liver and bile ducts are working and whether red blood cells are being broken down faster than usual. Newborns naturally handle bilirubin differently as their liver function matures, so their values and interpretation follow pediatric-specific considerations.

Clinicians use total bilirubin to evaluate yellowing of the skin or eyes, to investigate abnormal liver tests, and to monitor known liver or bile duct conditions. It can also help detect increased red blood cell breakdown, check for medication effects on the liver, and guide the need for imaging or additional testing.

Tracking bilirubin over time can show whether a problem is getting better or worse and whether treatment is working. In infants, careful assessment of bilirubin helps prevent complications related to developing liver function and higher turnover of red blood cells.

Your result is interpreted alongside your symptoms, examination, and other tests. A mild, stable elevation with otherwise normal liver tests may be benign in some people, such as those with a common inherited condition that affects bilirubin processing. Sudden changes, especially with tiredness, abdominal pain, dark urine, very pale stools, or yellowing of the eyes or skin, should be reviewed promptly.

If bilirubin is higher than expected, your clinician may order fractionated bilirubin to look at the direct and indirect portions, check liver enzymes, a complete blood count, and tests for red blood cell breakdown. They may also review medicines, alcohol use, fasting, or recent illness, and sometimes repeat the test when you are well hydrated and recovered. In newborns and young infants, pediatric teams follow specific pathways for assessment and follow-up.

Low bilirubin values are generally not concerning and usually do not require any action.