How should I interpret elevated bilirubin levels in the context of a patient's clinical presentation?

Interpretation of elevated bilirubin levels depends on the patient's age, clinical presentation, and associated laboratory findings.

In adults, elevated bilirubin, especially if >100 micromol/L, is a red flag requiring urgent referral or admission for secondary care assessment due to the risk of serious underlying conditions such as malignancy, liver disease, or biliary obstruction. Presence of jaundice with abnormal clotting, renal impairment, or suspicion of paracetamol overdose also mandates urgent evaluation. The clinical context (e.g., cholestatic vs hepatitic liver function test pattern) guides referral urgency and specialty (gastroenterology, hepatology, surgery). Well patients with known Gilbert's syndrome or confirmed hepatitis A may be managed in primary care, but unexplained jaundice always requires prompt referral ¹.

In newborns, interpretation of elevated bilirubin must consider gestational age, age in hours/days, feeding history, and clinical signs such as lethargy or poor feeding. Serum bilirubin levels should be measured urgently in visibly jaundiced babies, especially within the first 24 hours of life, as early jaundice is more likely pathological. Thresholds for intervention (phototherapy or exchange transfusion) depend on the baby's postnatal age and gestational maturity. Prolonged jaundice (>14 days in term babies) or conjugated hyperbilirubinaemia warrants further investigation for liver disease. Visual assessment alone is unreliable; serum bilirubin measurement is essential ²,³.

Summary: Elevated bilirubin in adults usually indicates serious pathology requiring urgent referral unless explained by benign causes like Gilbert's syndrome. In newborns, bilirubin levels must be interpreted relative to age and clinical risk factors to guide timely treatment and prevent complications such as kernicterus ¹,²,³.