Total Bilirubin

Total bilirubin is the sum of:

• Unconjugated (Indirect) bilirubin
• Conjugated (Direct) bilirubin

It is a key parameter in evaluating jaundice and liver function.

1️⃣ Diagnosis of Jaundice (Most Important)

Elevated total bilirubin indicates hyperbilirubinemia.

Normal value: 0.2 – 1.2 mg/dL

Clinical jaundice appears when total bilirubin > 2–3 mg/dL.

2️⃣ Differentiation of Types of Jaundice

A) Pre-hepatic (Hemolytic) Jaundice

• Cause: Excess RBC destruction
• ↑ Total bilirubin
• Mainly ↑ Unconjugated bilirubin
• No bilirubin in urine

Examples:

• Hemolytic anemia
• Malaria
• Mismatched blood transfusion

B) Hepatocellular Jaundice

• Cause: Liver cell damage
• ↑ Total bilirubin
• Both direct and indirect increased

Examples:

• Viral hepatitis
• Cirrhosis
• Drug-induced liver injury

C) Obstructive (Post-hepatic) Jaundice

• Cause: Bile duct obstruction
• ↑ Total bilirubin
• Mainly ↑ Direct bilirubin
• Bilirubin present in urine
• Pale stools

Examples:

• Gallstones
• Carcinoma head of pancreas
• Bile duct tumors

3️⃣ Neonatal Jaundice

• Physiological jaundice (unconjugated)
• Hemolytic disease of newborn
• Risk of kernicterus if very high

4️⃣ Monitoring Liver Disease

Total bilirubin helps:

• Assess severity of hepatitis
• Monitor liver failure
• Evaluate treatment response

5️⃣ Prognostic Value

Very high levels suggest:

• Severe liver failure
• Complete biliary obstruction