A Patient’s Guide to Understanding Rheumatoid Arthritis Testing & Monitoring

CRP, ESR, Vectra, and More: Learn about the main RA blood tests and what  they can — and can’t — reveal about your health

What Is Rheumatoid Arthritis Disease Activity?

Rheumatoid arthritis can be a progressive disease. This means that its effects on your body can worsen over time, which is called disease progression. Active RA can inflame and wear down your joints. Inflammation from active RA can damage your cardiovascular system and other organs such as your eyes, threatening your vision; or your lungs, leading to serious respiratory problems.

Treating RA promptly with a goal of reducing inflammation and disease activity is key. You and your doctor should work together to track, manage, and check RA disease progression with regular tests and a comprehensive treatment plan.

Diagnostic Tests: Tests That Help Diagnose RA

About CreakyJoints

This patient guide to rheumatoid arthritis tests was brought to you by CreakyJoints and Myriad Genetics, Inc., a molecular diagnostics company with corporate headquarters in Salt Lake City, Utah, which makes the Vectra test.

CreakyJoints is a digital community for millions of arthritis patients and caregivers worldwide who seek education, support, advocacy, and patient-centered research. We represent patients through our popular social media channels, our website CreakyJoints.org, and the 50-State Network, which includes nearly 1,500 trained volunteer patient, caregiver and healthcare activists.

As part of the Global Healthy Living Foundation, CreakyJoints also has a patient-reported outcomes registry called ArthritisPower® with nearly 25,000 consented arthritis patients who track their disease while volunteering to participate in longitudinal and observational research. CreakyJoints also publishes the popular “Raising the Voice of Patients” series, which are downloadable patient-centered navigational tools for managing chronic illness. For more information and to become a member (for free), visit CreakyJoints.org. To participate in our patient-centered research program, visit ArthritisPower.org.

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Part of the Global Healthy Living Foundation.

Explore the RA Blood Tests

Tests that measure RA antibodies and help diagnose RA


Tests that measure inflammation and help diagnose and monitor RA


Test that measures disease inflammation, activity, and predicts disease progression


Download the Patient’s Guide to Rheumatoid Arthritis Testing & Monitoring

There’s no single test used to diagnose RA; multiple diagnostic tests like anti-CCP and rheumatoid factor are used together to pinpoint RA as the cause of your symptoms, although a percentage of people with RA are “seronegative,” which means that they test negative for these two biomarkers.

What Is Rheumatoid Factor?
Rheumatoid factor is an autoantibody present in up to 80 percent of people with RA. It is linked to chronic inflammation and is typically used to help diagnose RA.
What’s Normal?

Normal or “negative” RF levels are less than 60 U/ml (units per milliliter), and any result higher than that may be considered “positive.” Older adults may have a higher threshold for normal levels of rheumatoid factor.

Rheumatoid Factor (RF)


Anti-Cyclic Citrullinated Peptide (Anti-CCP)

What Is Anti-CCP?
Anti-CCP are antibodies your body makes as an immune system reaction to an amino acid called citrulline, which is a byproduct of joint damage in RA. The higher the levels of anti-CCP in your blood, the more likely it is that you have RA inflammation. Anti-CCP may be more useful as a very specific way to diagnose RA, but not as useful for monitoring your ongoing disease activity. These antibodies may not tell us enough about how your RA disease activity goes up and down over time.

What’s Normal?

A normal anti-CCP result is less than 20 U/ml, and any result above that is “positive.” 


Prognostic Tests: Tests That Measure Inflammation

Some tests can help you get a clearer picture of your likely long-term prognosis with RA. This information can help you and your rheumatologist make treatment decisions and select more aggressive therapies early on to control your inflammation.

What Is Erythrocyte Sedimentation Rate?
Also called your “sed rate,” ESR tests how quickly red blood cells fall through whole blood samples in a tube. It’s a way to indirectly measure your inflammation. An ESR result of 100 mm/hour or higher indicates active disease.

What’s Normal?

Normal ESR results are 0-15 mm/hour in men under 50, 0-20 mm/hour in women under 50 or men older than 50, and 0-30 mm/hour in women older than 50.

Erythrocyte Sedimentation Rate (ESR or Sed Rate)


C-Reactive Protein (CRP)

What Is C-Reactive Protein?
CRP is a protein that is part of your immune system and its response to disease or external threats. CRP levels can also be high if you have active inflammation.

What’s Normal?
Normal CRP levels for adults are under 10 mg/L, and a higher result may indicate inflammation is present.


Test That Measures Inflammation & Disease Activity and Predicts Progression

Some tests can be predictive of your future outcomes with RA. If your test predicts that your disease is more likely to progress, then you and your rheumatologist can discuss changes to your therapy that may prevent this from happening.


What Is Vectra?
The Vectra test is a newer, more comprehensive, blood test that measures inflammation caused by your RA, predicts your risk of future joint damage (radiographic progression), and helps monitor disease and treatment.

While blood tests like ESR and CRP provide a single measure of inflammation, Vectra measures 12 different aspects of your blood — called biomarkers — that each play a different role in RA disease activity and inflammation. This combination of biomarkers can more accurately assess underlying inflammation — and predict the risk of future damage — than any single test.

The Vectra test can help assess how you are responding to your current therapy. It is a highly accurate way to assess RA disease progression, as well as predict future joint damage. The Vectra test also takes into account your age, adiposity (body fat composition) and sex, so it’s highly personalized. You can track changes in your Vectra Score over months or years.  


A Vectra score ranges from 1-100:

1-29: Low Disease Activity
30-44: Moderate Disease Activity
45-100: High Disease Activity

The Vectra score is a good way to assess how much underlying inflammation is happening in your body, even if you’re not aware of it. People with high disease activity are at a greater risk of having radiographic damage to their joints. Your doctor can use your Vectra score to adjust and optimize your treatment plan to endure your inflammation levels are in a low, healthy range.

Visit the official website to learn if Vectra can help you and your doctor manage your RA.

Download the Patient’s Guide to Rheumatoid Arthritis  Testing & Monitoring


Helpful Resources

The contents of this website are for informational purposes only and do not constitute medical advice. CreakyJoints.org is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a physician or other qualified health provider with any questions you may have regarding a medical condition.

How Do Doctors Diagnose, Test, and Track Rheumatoid Arthritis?

You and your rheumatologist have a variety of tools, both simple and sophisticated, to measure your inflammatory disease activity, monitor your disease progression, and track the success of your treatment plan at each appointment.

Many different tests are used in the diagnosis and management of rheumatoid arthritis. They all serve a different function in your patient journey. Test results can give you and your rheumatologist a snapshot of how you’re doing now, but some tests can also give some indication of how your disease may progress in the future.

The four main types of tests doctors use to manage rheumatoid arthritis include:

  • Physical Examination and Health Check
  • Blood Tests
  • Imaging Tests
  • Patient-Reported Outcomes (PROs)

If you have any questions about the tests you get at your doctor visits, ask your rheumatologist or nurse why they matter and how often they’re recommended. As a patient, you have a right to know why any medical recommendation is made for you, what any test involves, any out-of-pocket costs you will incur by taking a test, and if the test involves any pain or discomfort. Speak up, ask questions, and get the information you need to make the choices that are best for you.