Total Bilirubin

Measured in mg/dL

A waste product from the normal breakdown of red blood cells, processed by the liver — with a common, harmless inherited variation that can keep it mildly elevated.

What it is

Bilirubin is the yellowish pigment left over when your body recycles old red blood cells; your liver processes it and clears it into bile. Total bilirubin is read alongside liver enzymes (ALT, AST, alkaline phosphatase) and albumin, and it can be split into 'direct' and 'indirect' fractions to tell where in that pathway things are happening. A key caveat: mildly raised bilirubin is fairly common and is often explained by Gilbert's syndrome, a benign inherited trait affecting a meaningful slice of the population, and levels can also rise temporarily with fasting or illness.

Typical range

  • Adults0.0–1.2 mg/dL

Source · Mayo Clinic Laboratories (BILIT) (2026)

Reference ranges vary between laboratories, and what is normal for you depends on your own history. Your own lab’s range is the one printed on your report.

Worth asking your clinician

  • Is my bilirubin at a level you consider clinically meaningful, or within normal variation for me?
  • Would splitting it into direct and indirect bilirubin help explain this result?
  • Could fasting before the test, a recent illness, or any medications have affected this number?