Serum or plasma mass concentration of total bilirubin

Why Is This Test Done?

Your healthcare provider may order this test to check for conditions affecting the liver, bile ducts, or red blood cells. It can also help diagnose jaundice (yellowing of the skin and eyes), liver diseases like hepatitis, gallbladder problems, or hemolytic anemia (a condition where red blood cells break down too quickly).

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 involves a blood draw, but confirm with your provider. If you’re taking certain medications, let your lab know beforehand.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm. The sample is sent to a lab, where bilirubin levels are measured using a specialized method, often automated or enzymatic.

What Does the Result Mean?

Results are reported in units of mass concentration (e.g., mg/dL). High levels may indicate liver disease, bile blockage, or red blood cell disorders, while low levels are less common but could signal liver dysfunction or certain genetic conditions.