Serum or plasma concentration of total bilirubin

Why Bilirubin Matters in Your Health

Bilirubin is a byproduct of hemoglobin breakdown, which occurs naturally as old red blood cells are recycled. Normally, your liver processes and excretes bilirubin through bile. If bilirubin builds up in your blood, it can cause yellowing of the skin and eyes (jaundice). High levels may indicate liver disease, gallbladder issues, or other conditions affecting bile flow.

How the Test Works

Your blood sample is analyzed to measure bilirubin concentration. The test may use methods like enzymatic reactions or spectrophotometry to determine the amount. Results are compared to standard reference ranges to identify any abnormalities.

Common Conditions Linked to Bilirubin Levels

Elevated bilirubin often points to liver problems (e.g., hepatitis, cirrhosis), bile duct obstructions (e.g., gallstones), or hemolytic anemia (where red blood cells break down too quickly). Low levels are less common but may occur with certain liver diseases or medications.

What to Expect Before the Test

No special preparation is needed for this test. You may fast before the draw if instructed by your provider, but this depends on the lab’s protocol. Wear a comfortable shirt for easy access to your arm.