Total Bilirubin with Differential (Serum/Plasma)

Why Your Liver Matters

Your liver plays a vital role in processing nutrients, detoxifying chemicals, and producing bile—a yellow fluid that helps digest fats. When red blood cells break down, their waste product bilirubin is normally filtered by your liver. If bilirubin builds up, it can cause jaundice (yellowing of skin/eyes), itching, or fatigue.

What the Test Measures

Total bilirubin combines indirect (unconjugated) and direct (conjugated) forms. Indirect bilirubin travels in your blood until your liver processes it. Direct bilirubin is already water-soluble and can be excreted through bile. Abnormal levels may signal liver disease, gallbladder issues, or hemolysis (red blood cell destruction).

Common Causes of Abnormal Results

High bilirubin often appears when your liver struggles to process it (e.g., hepatitis, cirrhosis), bile ducts are blocked (e.g., gallstones), or red blood cells break down faster than usual (e.g., anemia). Low levels are less common but may occur with severe liver disease or certain medications.

When You Might Need This Test

Your doctor may order this test if you have symptoms like jaundice, unexplained fatigue, abdominal pain, or if they suspect liver/gallbladder problems during a routine checkup.