Total Bilirubin (Serum)

Why Is This Test Done?

Your healthcare provider may order this test to check for liver disease, bile duct blockages, or other conditions that affect how your liver processes bilirubin. It can also help diagnose conditions like hepatitis, jaundice, or hemolytic anemia, where red blood cells break down more quickly than usual.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it’s part of a liver function panel, but confirm with your lab or doctor. Bring any medications you’re taking, as some (like certain pain relievers) can affect results.

How the Test Is Performed

A blood sample is drawn from a vein, typically in your arm. The blood is sent to a lab where it’s analyzed to measure bilirubin levels using a specialized method (often nephelometry or turbidimetry). The result is reported in milligrams per deciliter (mg/dL).

What the Results Mean

High bilirubin levels (hyperbilirubinemia) may indicate liver problems, bile duct issues, or red blood cell disorders. Low levels are less common but can sometimes signal liver disease or other metabolic conditions. Your doctor will interpret results in the context of your overall health and symptoms.