Bilirubin Calculator
Calculate indirect bilirubin levels and assess jaundice type from total and direct bilirubin values
Calculate Bilirubin Levels
Medical Disclaimer
This calculator is for educational purposes only and should not replace professional medical advice. Elevated bilirubin levels require proper medical evaluation and diagnosis by a healthcare provider.
Normal range: 0.3-1.2 mg/dL
Normal range: 0-0.3 mg/dL
Bilirubin Calculation Results
Formula: Indirect Bilirubin = Total Bilirubin - Direct Bilirubin
Conversion: 1 mg/dL = 17.1 µmol/L
Example Calculation
Clinical Scenario
Patient: 45-year-old male presenting with jaundice
Total Bilirubin: 4.2 mg/dL (71.8 µmol/L)
Direct Bilirubin: 2.8 mg/dL (47.9 µmol/L)
Calculation
Indirect Bilirubin = 4.2 - 2.8
Indirect Bilirubin = 1.4 mg/dL (23.9 µmol/L)
Direct % = (2.8 / 4.2) × 100 = 66.7%
Interpretation: Conjugated hyperbilirubinemia suggesting hepatocellular injury or cholestasis. Further liver function tests recommended.
Normal Reference Ranges
Total Bilirubin
0.3-1.2 mg/dL
(5-21 µmol/L)
Direct Bilirubin
0-0.3 mg/dL
(0-5 µmol/L)
Indirect Bilirubin
0.2-0.9 mg/dL
(3-15 µmol/L)
Note: Ranges may vary by laboratory and patient population. Always use your laboratory's reference values.
Jaundice Assessment Tips
Jaundice becomes visible when total bilirubin exceeds 2.5 mg/dL
Direct bilirubin >50% suggests conjugated hyperbilirubinemia
Check scleral icterus in natural lighting for best assessment
Always correlate lab values with clinical presentation
Understanding Bilirubin and Jaundice
What is Bilirubin?
Bilirubin is a yellow-orange pigment produced during the normal breakdown of red blood cells. When red blood cells reach the end of their lifespan (about 120 days), they are broken down in the spleen, liver, and bone marrow. Hemoglobin from these cells is converted to bilirubin.
Types of Bilirubin
- •Indirect (Unconjugated) Bilirubin: Water-insoluble form that travels bound to albumin in the blood to the liver
- •Direct (Conjugated) Bilirubin: Water-soluble form created in the liver by conjugation with glucuronic acid, excreted in bile
- •Total Bilirubin: Sum of direct and indirect bilirubin
Bilirubin Metabolism
- 1. Hemolysis: Red blood cells break down releasing hemoglobin
- 2. Heme Conversion: Hemoglobin → Heme → Biliverdin → Unconjugated bilirubin
- 3. Transport: Unconjugated bilirubin binds to albumin in blood
- 4. Hepatic Uptake: Liver cells take up unconjugated bilirubin
- 5. Conjugation: Enzyme UDP-glucuronosyltransferase conjugates bilirubin
- 6. Excretion: Conjugated bilirubin excreted into bile
- 7. Intestinal Processing: Bacteria convert to urobilinogen and stercobilin
Clinical Significance: Problems at any step in this process can lead to elevated bilirubin levels and jaundice.
Clinical Classification of Hyperbilirubinemia
Unconjugated (Indirect) Hyperbilirubinemia
Direct bilirubin <20% of total. Indicates increased production or decreased hepatic uptake/conjugation.
Common Causes:
- • Hemolytic anemia
- • Gilbert's syndrome
- • Crigler-Najjar syndrome
- • Neonatal physiologic jaundice
- • Ineffective erythropoiesis
- • Large hematoma resorption
Conjugated (Direct) Hyperbilirubinemia
Direct bilirubin >50% of total. Indicates impaired hepatic excretion or biliary obstruction.
Common Causes:
- • Hepatitis (viral, alcoholic)
- • Cirrhosis
- • Bile duct obstruction (stones, tumor)
- • Primary biliary cholangitis
- • Dubin-Johnson syndrome
- • Drug-induced cholestasis
Mixed Hyperbilirubinemia
Direct bilirubin 20-50% of total. Combined features of both unconjugated and conjugated elevation.
Common Causes:
- • Severe hepatocellular disease
- • Sepsis
- • Heart failure with hepatic congestion
- • Advanced liver disease
- • Post-operative jaundice
- • Total parenteral nutrition
Diagnostic Approach to Hyperbilirubinemia
Step-by-Step Evaluation
1. Confirm Hyperbilirubinemia
- Measure total and direct bilirubin levels
- Physical examination for jaundice (scleral icterus, skin discoloration)
- Review medications and herbal supplements
2. Classify the Type
- Calculate direct bilirubin percentage
- Determine if predominantly unconjugated, conjugated, or mixed
- Consider timing and onset (acute vs. chronic)
3. Order Additional Tests
For Unconjugated:
- Complete blood count (CBC)
- Peripheral blood smear
- Reticulocyte count
- LDH, haptoglobin
- Coombs test
For Conjugated:
- Liver function tests (AST, ALT, ALP)
- GGT (gamma-glutamyl transferase)
- Prothrombin time/INR
- Albumin
- Hepatitis serologies
4. Consider Imaging
- Ultrasound: First-line imaging for biliary tree evaluation
- CT/MRI: For detailed hepatobiliary anatomy
- MRCP: Non-invasive cholangiography
- ERCP: Therapeutic and diagnostic for bile duct issues
5. Specialized Testing if Needed
- Liver biopsy for unclear diagnoses
- Genetic testing for inherited disorders
- Autoimmune markers (ANA, AMA, ASMA)
- Ceruloplasmin for Wilson's disease
Common Conditions Causing Hyperbilirubinemia
Gilbert's Syndrome
Prevalence: 3-7% of population, most common inherited cause
Mechanism: Reduced UDP-glucuronosyltransferase activity (30% of normal)
Bilirubin Pattern: Mild unconjugated hyperbilirubinemia (1-3 mg/dL)
Clinical Features: Benign condition, no treatment needed, may worsen with fasting or illness
Prognosis: Excellent, normal life expectancy, no liver damage
Hemolytic Anemia
Mechanism: Accelerated red blood cell destruction exceeding liver's conjugation capacity
Bilirubin Pattern: Predominantly unconjugated, rarely exceeds 5 mg/dL unless liver disease coexists
Associated Findings: Anemia, elevated LDH, low haptoglobin, reticulocytosis, splenomegaly
Treatment: Address underlying cause (autoimmune, hereditary, drug-induced)
Viral Hepatitis
Mechanism: Hepatocellular injury causing impaired conjugation and excretion
Bilirubin Pattern: Mixed pattern, often >5 mg/dL in acute phase
Associated Findings: Elevated ALT/AST (often >500 U/L), positive viral serologies
Management: Supportive care for acute hepatitis, antivirals for chronic cases
Biliary Obstruction
Common Causes: Gallstones, pancreatic cancer, cholangiocarcinoma, primary sclerosing cholangitis
Bilirubin Pattern: Predominantly conjugated, may exceed 20 mg/dL
Associated Findings: Elevated ALP and GGT (cholestatic pattern), dilated bile ducts on imaging
Treatment: ERCP with stone extraction or stenting, surgical intervention for malignancy
Treatment and Management of Hyperbilirubinemia
General Management Principles
- ✓Identify and Treat Underlying Cause: Target specific etiology (hemolysis, hepatitis, obstruction)
- ✓Monitor Liver Function: Serial measurements of bilirubin, transaminases, and coagulation parameters
- ✓Discontinue Hepatotoxic Medications: Review and stop potentially offending drugs
- ✓Nutritional Support: Ensure adequate calories, avoid alcohol
- ✓Address Complications: Manage pruritus, coagulopathy, encephalopathy
Specific Interventions
Neonatal Jaundice:
- Phototherapy for unconjugated hyperbilirubinemia
- Exchange transfusion for severe cases
- Ensure adequate feeding and hydration
Biliary Obstruction:
- ERCP with sphincterotomy and stone extraction
- Biliary stenting for malignant obstruction
- Surgical resection when appropriate
Hemolytic Anemia:
- Corticosteroids for autoimmune hemolysis
- Splenectomy for hereditary spherocytosis
- Transfusion support as needed
⚠️ When to Seek Immediate Medical Attention
Emergency Symptoms
- ⚠Sudden onset of severe jaundice
- ⚠Dark urine with pale stools
- ⚠Severe abdominal pain
- ⚠Fever with jaundice
- ⚠Confusion or altered mental status
- ⚠Easy bruising or bleeding
Routine Medical Evaluation Needed
- •Persistent yellow discoloration of skin or eyes
- •Unexplained fatigue or weakness
- •Loss of appetite or weight loss
- •Persistent itching
- •Family history of liver disease or blood disorders
- •Alcohol or substance abuse history
Important: This calculator provides educational information only. Elevated bilirubin levels can indicate serious medical conditions requiring professional evaluation. Always consult a healthcare provider for proper diagnosis and treatment of hyperbilirubinemia.
Frequently Asked Questions
What does elevated bilirubin mean?
Elevated bilirubin (hyperbilirubinemia) means your blood contains higher than normal levels of bilirubin, a yellow pigment produced during red blood cell breakdown. When levels exceed 2.5 mg/dL, it typically causes jaundice (yellowing of skin and eyes). The pattern of elevation helps determine the underlying cause.
What's the difference between direct and indirect bilirubin?
Indirect (unconjugated) bilirubin is fat-soluble and travels bound to albumin. It's formed from red blood cell breakdown and hasn't been processed by the liver yet.Direct (conjugated) bilirubin is water-soluble and has been processed by the liver through conjugation with glucuronic acid. It can be excreted in bile and gives urine a dark color when elevated.
Is high bilirubin always serious?
Not always. Gilbert's syndrome, affecting 3-7% of the population, causes mild unconjugated hyperbilirubinemia (usually 1-3 mg/dL) but is completely benign and requires no treatment. However, significantly elevated bilirubin, rapidly rising levels, or conjugated hyperbilirubinemia often indicates serious conditions requiring medical evaluation.
How is hyperbilirubinemia treated?
Treatment depends on the underlying cause. Unconjugated hyperbilirubinemia from hemolysis may require treating the blood disorder. Conjugated hyperbilirubinemia from biliary obstruction might need ERCP or surgery. Viral hepatitis requires supportive care or antivirals. Neonatal jaundice is often treated with phototherapy. The key is identifying and addressing the root cause.
Can diet affect bilirubin levels?
Fasting can temporarily raise unconjugated bilirubin levels, especially in Gilbert's syndrome. A high-fat diet may worsen symptoms in cholestatic conditions. However, diet is rarely the primary cause of significantly elevated bilirubin. Alcohol should be avoided as it can worsen liver disease. Staying hydrated and maintaining adequate nutrition supports liver function.
When does jaundice become visible?
Jaundice typically becomes clinically visible when total bilirubin exceeds 2.5-3 mg/dL (43-51 µmol/L). It's usually first noticed in the sclera (whites of the eyes) before appearing in the skin. The yellowish discoloration is best observed in natural lighting. Darker skin tones may require closer examination of the sclera, palms, and mucous membranes.