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Bile Pigment

Urine Analysis Biomarker

Sample Needed

Collection Type: Urine

Body System

Related System: Urine Analysis

Overview

Bile pigment in a urine test refers primarily to bilirubin (the water‑soluble, conjugated form) and related biliary pigments that may appear in urine when the liver’s ability to excrete bilirubin into bile is impaired or bile flow is obstructed. The urine test detects bilirubin (and, separately, urobilinogen patterns) as a sign of hepatobiliary disease. Positive urine bile pigment suggests conjugated hyperbilirubinemia from causes such as hepatitis, biliary obstruction (stones, strictures, tumors), cholestasis, or advanced cirrhosis. Symptoms prompting testing include jaundice, dark urine, pale stools, abdominal pain, itching, nausea, and fatigue. Newborns commonly have unconjugated hyperbilirubinemia that does not show in urine; otherwise, age and underlying disease (e.g., cholestatic disorders more common in older adults) influence results, while gender has little direct effect.

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Test Preparation

Collect a Random/Spot urine sample in a sealed and sterile screw-capped container provided by our sample collection professional
Women are advised not to give the sample during the menstrual period unless prescribed
Blood contaminated and highly turbid samples are not acceptable

Why Do I Need This Test

Which profile is the test included in: Urine Analysis (urinalysis) / Urine dipstick testing.
Symptoms that may indicate the test: jaundice, dark urine, pale stools, pruritus, right‑upper‑quadrant pain, unexplained fatigue.
Conditions it may diagnose/monitor: obstructive jaundice, hepatitis, cholestasis, cirrhosis, bile duct stones or tumors, some inherited conjugation/excretion disorders.
Reasons for abnormal levels: impaired hepatic uptake/excretion or mechanical bile duct obstruction causing conjugated bilirubin to spill into blood and be filtered by kidneys.
Biological meaning of abnormal values: presence of bilirubin in urine means conjugated (water‑soluble) bilirubin is elevated systemically—reflects liver excretory failure or obstruction.
Behaviors/lifestyle causing abnormal values: heavy alcohol use, hepatotoxic drugs, anabolic steroids, some herbal supplements.
Family history: inherited cholestatic syndromes (e.g., Rotor or Dubin‑Johnson) or familial biliary tract disorders warrant testing.

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Understanding Test Results

Any detectable bilirubin (bile pigment) in urine is considered abnormal.
A positive urine bilirubin usually indicates conjugated serum bilirubin has exceeded the renal-excretory threshold typically when serum conjugated bilirubin is ≈1.2–2.0 mg/dL (≈20–34 μmol/L) or higher.
Trace/1+ urine bilirubin suggests mild cholestasis or early hepatocellular impairment; 2+ to 3+ suggests moderate to severe obstruction or marked hepatic excretory failure.
Extremely high serum conjugated bilirubin (for example >5 mg/dL or >85 μmol/L) commonly produces strongly positive urine tests and indicates significant cholestasis or liver dysfunction requiring prompt evaluation.
Absence of urine bilirubin with jaundice favors unconjugated hyperbilirubinemia (e.g., hemolysis or neonatal physiologic jaundice).
Note false negatives can occur if urine is exposed to light or contains large amounts of ascorbic acid (vitamin C); false positives may occur with some bile‑colored drugs or porphyrins.
Further blood tests (serum bilirubin fractionation, liver enzymes, imaging) are needed to determine the cause.

Normal Range

Negative OR 0 mg/dL

FAQs

Q: What is the bile pigment?

A: The primary bile pigment is bilirubin, a yellow‑green compound produced when heme from aged red blood cells is broken down. Unconjugated bilirubin travels to the liver, is conjugated to become water‑soluble, and is excreted in bile into the intestines. Gut bacteria convert it to stercobilin, which colors stool; impaired processing or excretion leads to jaundice.

Q: What is the main bile pigment called?

A: The main bile pigment is bilirubin. It’s produced by breakdown of hemoglobin from aged red blood cells, initially as unconjugated (indirect) bilirubin, transported to the liver where it’s conjugated (made water‑soluble) and excreted into bile. Bilirubin gives bile its yellow‑green color; elevated levels cause jaundice and indicate liver, bile duct, or hemolytic disorders.

Q: What is a normal bile pigment level?

A: Normal total bile pigment (bilirubin) is typically about 0.3–1.2 mg/dL (5–20 µmol/L). Mild deviations can reflect lab variation; higher levels suggest liver dysfunction, bile duct obstruction, or increased red cell breakdown. Direct (conjugated) and indirect (unconjugated) bilirubin are reported separately. Interpretation depends on symptoms and other liver tests—see a clinician if levels are elevated.

Q: What is the difference between bile salts and bile pigments?

A: Bile salts are amphipathic, cholesterol-derived molecules (conjugated bile acids) made in the liver that emulsify dietary fats and form micelles to aid absorption; they undergo enterohepatic recycling. Bile pigments are heme‑breakdown products (mainly bilirubin) from hemoglobin catabolism, conjugated in the liver and excreted in bile; they color bile and eliminate waste but do not aid fat digestion.

Q: Is bile pigment serious?

A: Bile pigments (mainly bilirubin) themselves aren’t always serious, but high levels causing jaundice can indicate liver disease, bile-duct obstruction, or hemolysis. Mild elevations may be benign; rapid rise, very high levels, pale stools, dark urine, abdominal pain, fever, itching or confusion require urgent evaluation. Diagnosis and treatment depend on the underlying cause, so see a healthcare professional promptly if symptoms appear.

Q: Where are bile pigments made?

A: Bile pigments are produced during heme breakdown in the reticuloendothelial system—mainly splenic and bone marrow macrophages and liver Kupffer cells. Heme is converted to biliverdin by heme oxygenase, then reduced to unconjugated bilirubin. Unconjugated bilirubin is transported to hepatocytes, where it is conjugated (glucuronidated) and excreted into bile. Impaired conjugation or excretion leads to jaundice.