Can this result diagnose a condition on its own?

No. The result should be interpreted with symptoms, medical history, assay method and related tests.

Which reference range should I use?

Use the performing laboratory's own reference or decision range and reporting method first.

When should I discuss the result with a healthcare professional?

Reactive/positive, clearly abnormal, persistent or symptom-associated results should be reviewed by a healthcare professional.

Information about a laboratory test

Rheumatoid Factor What Does This Test Mean?

Rheumatoid Factor measures rheumatoid factor in blood.

Test summary

Test name: Rheumatoid Factor
Abbreviations: RF
Category: Autoimmunity / Rheumatology
Panel: Rheumatoid Arthritis Evaluation
Specimen: Serum / plasma
Common units: IU/mL, qualitative

What does the test measure?

Rheumatoid Factor measures rheumatoid factor in blood.

Why is the test ordered?

Rheumatoid Factor is used with anti-CCP and clinical findings when evaluating rheumatoid arthritis and some other conditions.

Information about a low result

Normal/low RF does not completely rule out rheumatoid arthritis.

Information about a high result

High RF can occur in rheumatoid arthritis but also in other diseases and some healthy people.

Reference and clinical context

Start with the performing laboratory's reference or decision range, assay method, specimen and reporting unit. A single result usually does not establish a diagnosis on its own.

Reference ranges may vary by laboratory, method used, age, sex, pregnancy status, and clinical context. The reference range on your own laboratory report takes precedence.

Interpretation notes

RF does not diagnose rheumatoid arthritis by itself; anti-CCP, inflammatory markers and clinical findings matter.

Related specialties

Rheumatology
Internal Medicine

Frequently asked questions

More information about this test

Rheumatoid Factor High Result: What Does It Mean?

Sources

ANA (Antinuclear Antibody) Test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2025 · ANA purpose, positive/negative interpretation and limitations · Verified: Aug 12, 2026
Rheumatoid Factor (RF) Test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2025 · RF use, high-result limitations and RA context · Verified: Aug 12, 2026
CCP Antibody Test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2024 · Anti-CCP use and rheumatoid arthritis evaluation · Verified: Aug 12, 2026