Getting a diagnosis for rheumatoid arthritis (RA) isn’t as simple as taking one test. Doctors look at the whole picture — your symptoms, how your joints feel and move during an exam, your medical and family history, and the results of blood work and imaging scans. This combination of information helps doctors spot signs of RA and rule out other conditions that can cause similar symptoms.

Because RA is a chronic (long-term) autoimmune condition that affects joints and sometimes other parts of the body, you may see a rheumatologist for diagnosis. These specialists are trained to recognize the patterns of RA, interpret test results, and confirm whether your symptoms fit the diagnosis so you can get started on the right treatment plan.

Continue reading to learn more about the RA diagnostic process.

What Tests Are Done To Diagnose Rheumatoid Arthritis?

Since there are numerous tests for RA, the American College of Rheumatology and European League Against Rheumatism (EULAR) joint working group has established certain classification criteria that help healthcare providers guide the diagnosis of the condition. These criteria helps providers assess physical exam findings, imaging, and blood tests.

Physical Exam

Typically, your healthcare provider will start by examining your joints to check for signs of disease activity, such as joint swelling, limited range of motion of your joints, redness or discoloration (a sign of redness), and warmth. In RA, symptoms are symmetrical, appearing on the same joints on both sides of the body. However, early signs and symptoms of RA may not be symmetrical, so it’s important to see a rheumatologist who’s familiar with the stages of disease.

You may be asked about what time of day you experience symptoms — morning stiffness is common in RA.

You may also be asked about family medical history of RA or other autoimmune diseases. According to Mayo Clinic, having relatives with autoimmune disorders is one risk factor for developing RA.

Imaging

Diagnosis may also involve imaging tests such as X-rays, ultrasound scans, magnetic resonance imaging (MRI) scans, or computed tomography (CT) scans. Scans allow the doctor to check for joint damage during diagnosis and later measure how the disease progresses over time. Ultrasound and MRI imaging can detect more subtle joint damage that may lead to an earlier diagnosis.

Lab Tests

Although no one lab test is conclusive for rheumatoid arthritis, several individual tests can provide important clues that make an RA diagnosis seem more likely or help rule it out.

Anti-Cyclic Citrullinated Peptide

Blood tests can check for certain proteins that work as biomarkers (signs) of rheumatoid arthritis. One of these signs is an autoantibody called anti-cyclic citrullinated peptide (anti-CCP). This protein can be in the blood before RA symptoms start, which can help diagnose the condition early on.

Rheumatoid Factor

Blood tests can check for rheumatoid factor (RF), an autoantibody that is often found in people with RA. However, having RF in your blood doesn’t automatically mean you have rheumatoid arthritis — it can also appear in people with other autoimmune or chronic conditions, and even in some healthy individuals. When RF is present, it suggests that the immune system may be mistakenly attacking the body’s own tissues, a sign of an autoimmune response.

Inflammation Tests

Blood tests can also check overall levels of inflammation. These tests are erythrocyte sedimentation rate (ESR or “sed rate”) and C-reactive protein (CRP). At elevated levels, both ESR and CRP are considered signs of inflammation and can indicate RA or another inflammatory condition.

Other Blood Tests

Your doctor may order other tests to check your liver, kidney, and thyroid function and other levels in your body. Anemia (low red blood cell count) is another condition often seen in people with RA. All of these tests can be clues to your diagnosis.

Other Conditions That Mimic Rheumatoid Arthritis

Rheumatoid arthritis may be misdiagnosed, especially at an early stage when the symptoms are mild. Joint pain in RA can resemble other chronic diseases, including lupus, ankylosing spondylitis, Sjögren’s disease, and gout. It could also be misdiagnosed as other types of arthritis, like psoriatic arthritis and osteoarthritis. A doctor carefully considers multiple test results and various joint diseases before making a diagnosis of RA or ruling it out.