What is bilirubin?
When red blood cells reach the end of their 120-day lifespan, they are broken down in the spleen. The haemoglobin releases a yellow pigment called bilirubin. This travels to the liver, gets processed (conjugated), and is excreted in bile into the gut — giving stools their brown colour and contributing to the yellow colour of urine. When this pathway is disrupted at any point, bilirubin builds up in the blood, causing jaundice.
Types of bilirubin in your report
| Test | Normal Range (mg/dL) | What it measures |
|---|---|---|
| Total Bilirubin | 0.2 – 1.2 | All bilirubin combined |
| Direct (Conjugated) | 0.0 – 0.3 | Processed by liver — bile duct problem if high |
| Indirect (Unconjugated) | 0.2 – 0.9 | Pre-liver — haemolysis or Gilbert's if high |
What does HIGH total bilirubin mean?
HIGH Total bilirubin above 1.2 mg/dL
Jaundice (yellow skin/eyes) becomes visible when total bilirubin exceeds 2.5–3 mg/dL. Causes depend on WHICH type is elevated:
High INDIRECT bilirubin — pre-liver causes
High indirect bilirubin
Gilbert's Syndrome (most common — affects 5–10% of people, harmless): mildly elevated indirect bilirubin that fluctuates with fasting, stress or illness. No treatment needed. Haemolytic anaemia: red blood cells being destroyed faster than the liver can process bilirubin. Causes: sickle cell disease, thalassaemia, G6PD deficiency, autoimmune haemolysis. Neonatal jaundice: very common in newborns — immature liver can't process bilirubin fast enough.
High DIRECT bilirubin — liver/bile duct causes
High direct bilirubin
High direct (conjugated) bilirubin means the liver has processed it but can't excrete it — a bile duct blockage or liver cell damage. Causes: gallstones blocking the bile duct (most common surgical cause), viral hepatitis (A, B, E), alcoholic hepatitis, cholestasis of pregnancy, pancreatic cancer compressing the bile duct (painless jaundice in elderly = investigate urgently), primary biliary cholangitis.
Questions to ask your doctor
- Is my bilirubin rise direct or indirect — and what does that narrow it down to?
- Do I need a liver ultrasound to check for gallstones or bile duct dilation?
- Could this be Gilbert's syndrome — a harmless condition?
- Should I test for Hepatitis A, B and E?