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Interleukin-6 (IL-6) concentration in serum/plasma

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

This test measures the amount of interleukin-6, a protein involved in inflammation and immune response, found in your blood.

Quick summary

["IL-6 helps your body respond to infection, injury, or chronic conditions like arthritis."]

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

Key facts at a glance

LOINC
49067-2
Short code
LACV IgG+IgM CSF-Imp
Synonyms
LACV IgG+IgM CSF-Imp
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your doctor may order this test to check for signs of inflammation, autoimmune diseases, infections, or certain cancers. It can also help monitor conditions like rheumatoid arthritis, lupus, or after treatments for blood cancers.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm to draw blood. If you’re on blood thinners, let your doctor know before the test.

What the Results Mean

Higher than normal levels may suggest inflammation, infection, or autoimmune activity. Lower levels might indicate suppressed immune response, though this is less common. Your doctor will interpret results in the context of your health history.

Common Conditions Monitored

IL-6 levels are often checked in people with chronic inflammatory diseases, such as rheumatoid arthritis or lupus, or those undergoing cancer treatments like chemotherapy.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

IL-6 plays a key role in the body’s immune response and inflammation. Elevated levels can indicate active inflammation, infections, or certain cancers. Doctors use these results to guide treatment decisions, especially for autoimmune or inflammatory conditions.

Short name

IL-6 Level

Frequently asked questions

What causes IL-6 levels to be high?
High IL-6 levels can be caused by infections, autoimmune diseases (like rheumatoid arthritis or lupus), certain cancers, or severe injuries. Stress or certain medications may also affect it.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab.
Can diet or exercise affect IL-6 levels?
Diet and exercise can influence inflammation, but IL-6 levels are measured in a blood sample taken at a specific time. Your doctor may recommend fasting if instructed, but this test does not require strict dietary restrictions.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 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