Total Bilirubin Index (Icteric Index) – Serum/Plasma
This test measures the overall bilirubin level in your blood, which helps assess liver function and detect jaundice (yellowing of the skin or eyes).
["Your doctor may use this test to check for liver issues or blockages in bile flow."]
Key facts at a glance
- LOINC
- 97199-4
- Short code
- Icteric interf index CSF-aCnc
- Synonyms
- Icteric interf index CSF-aCnc
- Category
- chemistry
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 86430
- Specimen volume
- 1-2 mL
- Stability
- Immediate analysis required, Refrigerated: 1h
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
What Does This Test Measure?
Bilirubin is a yellow pigment produced when red blood cells break down. It’s normally processed by the liver and excreted in bile. An elevated bilirubin level can indicate problems like liver disease, gallbladder issues, or hemolysis (destruction of red blood cells). This test specifically evaluates the total bilirubin concentration in your blood, which can be influenced by direct (conjugated) and indirect (unconjugated) forms.
Why Might Your Doctor Order This Test?
Your doctor may request this test if you have symptoms like jaundice (yellowing of skin/eyes), dark urine, pale stools, or if they suspect liver disease, bile duct obstruction, or other conditions affecting bilirubin metabolism. It’s also used in monitoring certain treatments or conditions.
How Is This Test Performed?
A blood sample is drawn from a vein, usually in your arm. The sample is then sent to a lab for analysis. The test measures the total bilirubin concentration in your serum or plasma, which is reported as a numerical value (though reference ranges vary by lab).
What Are Common Causes of Abnormal Results?
Elevated bilirubin levels can result from liver diseases (e.g., hepatitis), bile duct blockages (e.g., gallstones), hemolytic anemia, or certain medications. Low levels may occur in newborns due to immature liver function or rarely in adults with liver disorders.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is critical for diagnosing and managing conditions affecting bilirubin metabolism. High levels often signal underlying liver or bile-related issues, while low levels may require further investigation to rule out conditions like newborn jaundice or rare metabolic disorders. Early detection can guide treatment decisions, such as managing liver inflammation or addressing bile flow obstructions.
Short name
Bilirubin Index
Frequently asked questions
How long does it take to get results?
What does a high bilirubin level mean?
Can diet affect bilirubin levels?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy