✍️ Written by the MedTestBD Editorial Team · Last reviewed: July 2026
What is the Serum Bilirubin Test?
The serum bilirubin test measures the level of bilirubin — a yellow pigment produced when red blood cells break down — in the blood. The liver processes bilirubin and excretes it in bile. When bilirubin accumulates in the blood, it causes jaundice — yellowing of the skin and eyes. The test measures three values: total bilirubin, direct (conjugated) bilirubin, and indirect (unconjugated) bilirubin, which together help identify the cause of jaundice.
Why is the Serum Bilirubin Test Done?
- To investigate jaundice — yellowing of the skin, eyes, or urine
- To diagnose and monitor liver diseases such as hepatitis, cirrhosis, or bile duct obstruction
- To evaluate newborn jaundice — high bilirubin in newborns can cause brain damage if untreated
- To detect haemolytic anaemia — increased red blood cell destruction raises indirect bilirubin
- As part of a routine liver function panel (LFT) alongside SGPT, SGOT, and ALP
- To monitor patients on medications that affect the liver
Normal Serum Bilirubin Levels
| Type | Normal Range |
|---|---|
| Total Bilirubin | 0.2 – 1.2 mg/dL |
| Direct (Conjugated) Bilirubin | 0.0 – 0.3 mg/dL |
| Indirect (Unconjugated) Bilirubin | 0.2 – 0.9 mg/dL |
Elevated direct bilirubin points to a problem in the liver or bile ducts — such as gallstones blocking bile flow or hepatitis. Elevated indirect bilirubin suggests excessive red blood cell breakdown (haemolysis) or a condition like Gilbert's syndrome, which is a harmless inherited condition causing mildly elevated bilirubin. Your doctor will interpret both fractions together with other liver tests.
How to Prepare for the Serum Bilirubin Test
- Fasting for 4 hours before the test is generally recommended — eating can temporarily lower bilirubin levels
- Avoid prolonged exposure to direct sunlight before the test — light breaks down bilirubin and can lower the measured value
- Inform your doctor about all medications you take, especially those known to affect the liver
- A simple blood sample is drawn from a vein in your arm
Serum Bilirubin Test Price in Bangladesh
Serum bilirubin test prices vary between diagnostic centers across Bangladesh. Compare serum bilirubin test prices on MedTestBD →
⚠️ This information is for general reference only. Always consult a qualified physician before undergoing any medical test.
