Serum or plasma mass concentration of total bilirubin

Published: August 9, 2026Updated: August 16, 2026

This test measures the total amount of bilirubin in your blood, a yellow pigment produced when red blood cells break down. It helps assess liver function and detect conditions like jaundice or bile duct blockages.

Quick summary

["Bilirubin levels can signal liver or bile flow issues."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC: 12490-9
Short code: Talbutal SerPl-mCnc
Synonyms: Talbutal SerPl-mCnc
Category: chemistry
Sample: serum
Container: Red-top tube (SST)
Units: N/A
Fasting: false
Population: adult
Sex: all
Age range: 18–65 years
Specimen volume: 5 mL
Stability: Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max: 500
Lipemia max: 1000
Icterus max: 500
TAT: 4–24 hours
Order: routine

Why This Test Matters

Bilirubin is a normal byproduct of red blood cell breakdown, but high levels can indicate problems with your liver, gallbladder, or bile ducts. Your doctor may order this test if you have symptoms like jaundice (yellowing of skin/eyes), fatigue, or unexplained dark urine.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample (serum or plasma) or, less commonly, urine. If you’re on certain medications (e.g., antibiotics, painkillers), mention it to your provider, as they may affect results.

Common Causes of Abnormal Results

Elevated bilirubin may stem from liver diseases (e.g., hepatitis), gallbladder issues (e.g., stones), or hemolytic anemia (rapid red blood cell destruction). Low levels are less common but could signal liver dysfunction or certain genetic disorders.

When Results Might Be Different

Results can vary based on specimen type (serum vs. plasma) or testing method. For example, plasma samples may show slightly different values than serum due to clotting factors. Your lab will specify the method used.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Total bilirubin

Frequently asked questions

What does a high bilirubin level mean?

A high bilirubin level often points to **hepatobiliary** problems (liver, bile ducts, or gallbladder). For example, it may signal liver inflammation (hepatitis), bile duct obstruction, or red blood cell disorders. Your doctor will evaluate symptoms and other tests (e.g., liver enzymes) to diagnose the cause.

What if my bilirubin is low?

Low bilirubin is less common but can occur with severe liver disease (e.g., cirrhosis) or certain genetic conditions. It may also be incidental if your liver isn’t processing bilirubin normally. Your provider will discuss findings in context with your overall health.

Does diet affect this test?

Dietary factors like vitamin K (found in leafy greens) or certain medications (e.g., antacids) can influence bilirubin indirectly. However, avoid extreme dietary changes before testing. Your doctor may advise fasting if your test involves a urine sample.

Sources

1
MedlinePlus — Laboratory TestsSource
2
Lab Tests OnlineSource
3
Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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