LFT Biomarker
Collection Type: Blood
Related System: LFT
Total bilirubin is the combined measure of unconjugated (indirect) and conjugated (direct) bilirubin in blood. Bilirubin is a breakdown product of heme from red blood cells processed by the liver for excretion in bile. The total bilirubin test evaluates liver function, bile flow, and red blood cell destruction. Elevated levels may suggest hemolysis, hepatocellular injury (hepatitis, cirrhosis), or biliary obstruction; mild isolated increases can reflect benign inherited conditions (e.g., Gilbert syndrome). Symptoms prompting testing include jaundice, dark urine, pale stools, abdominal pain, fatigue, or unexplained itching. Newborns normally have higher bilirubin; values are otherwise similar across adult ages and between sexes, though pregnancy and certain medications can alter results.
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Symptom Checker0.3-1.2 mg/dL OR 5.1-20.5 μmol/L
Q: What does it mean when total bilirubin is high?
A: High total bilirubin means excess bilirubin in blood, indicating increased red blood cell breakdown, impaired liver uptake/conjugation, or blocked bile excretion. Common causes include hemolysis, inherited conjugation defects (e.g., Gilbert), acute or chronic liver disease, and bile duct obstruction. It often causes jaundice, dark urine, pale stools, and itching; further tests determine the exact cause and guide treatment.
Q: What levels of bilirubin are concerning?
A: Normal total bilirubin is about 0.1–1.2 mg/dL. In adults, levels above 2–3 mg/dL usually produce visible jaundice and require evaluation; levels >5 mg/dL suggest significant liver dysfunction. In newborns, concern is age-dependent: term infants with total bilirubin above about 15 mg/dL need prompt assessment, and levels above 20–25 mg/dL carry risk of bilirubin encephalopathy (kernicterus).
Q: What happens if total bilirubin is low?
A: Low total bilirubin is usually clinically insignificant and causes no symptoms. It can reflect decreased red‑cell breakdown, recent transfusion or dilution (overhydration), or result from certain medications or lab variation. Rarely it indicates altered bilirubin metabolism. Persistent low values or any worrying symptoms should prompt evaluation of liver function, blood counts and medications by a clinician.
Q: What is the normal range of bilirubin in pregnancy?
A: In pregnancy, total bilirubin is expected to remain within the usual non‑pregnant range roughly 0.3–1.2 mg/dL (5–20 µmol/L). Small fluctuations can occur, but levels consistently above ~1.2 mg/dL (≈20 µmol/L) or rising with symptoms such as pruritus should prompt further evaluation for liver disease or intrahepatic cholestasis of pregnancy. Discuss any abnormal results with your clinician.
Q: What is total bilirubin?
A: Total bilirubin is the combined amount of unconjugated (indirect) and conjugated (direct) bilirubin in the blood. Bilirubin is a yellow pigment produced when old red blood cells are broken down; the liver processes and excretes it into bile. Elevated total bilirubin can indicate liver disease, bile duct obstruction, or increased red-cell breakdown and often causes jaundice, prompting medical evaluation.
Q: What is an alarming bilirubin count?
A: An alarming bilirubin count is generally total bilirubin above about 3 mg/dL in adults, which suggests significant liver dysfunction or bile-duct obstruction and needs prompt evaluation. In newborns, levels above roughly 20 mg/dL are dangerous because of the risk of brain injury (kernicterus). Any rapid rise, values outside the lab reference range, or symptoms (jaundice, dark urine, pale stools, confusion) requires urgent assessment.