Rheumatoid Arthritis Diagnosis
How Your Doctor Will Diagnose RA
During your first visit with your rheumatologist, he or she will try to figure out whether you have RA or some other health condition that explains your symptoms. There are some key tools that your doctor will use in diagnosing the disease. These include:
- Medical history
- Physical examination
- Diagnostic testing (laboratory testing and imaging)
RA diagnostic criteria
Diagnosis of RA is made primarily using results from the physical examination. However, there are a number of findings from laboratory testing and imaging, as well as your medical history that may help your doctor determine whether you have RA.
Your doctor will use the results from your assessment to see if you satisfy the diagnostic criteria for RA. RA cannot be diagnosed on the basis of a single test or symptom. Two key medical organizations involved in RA diagnosis and treatment in the US and Europe, the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR), respectively, recently updated the criteria used to diagnose RA. These criteria, published in 2010, built on earlier diagnostic criteria first introduced by the ACR in 1987. The new 2010 criteria include1,2:
In the ACR/EULAR 2010 Criteria, each criterion is associated with a point value. Diagnosis of RA can be made when a total of 6 points is reached across the 9 separate criteria.1,2
Diagnosis of RA: ACR/EULAR 2012 Criteria
- Stiffness and swelling in at least 1 joint not explain by another condition
- 1 large joint
- 2-10 large joints
- 1-3 small joints (with or without a large joint )
- 4-10 small joints (with or without a large joint )
- >10 small joints (with or without a large joint )
- RF negative and ACPA negative
- RF low-positive or ACPA positive
- RF high-positive or ACPA positive
- Normal CRP and ESR
- Abnormal CRP or ESR
- Less than 6 weeks
- 6 weeks or longer
When your doctor takes your medical history, he or she will ask you questions covering several key areas. These will include questions about your symptoms, family medical history, other medical problems you may have, and any medications you are taking. Before you show up for this first visit, gather your thoughts and collect information relevant to each of these topics. It also helps to bring some paper and a pencil or pen to take notes. Sometimes during a doctor’s visit—because of the stress involved—it is difficult to absorb everything you discuss and what recommendations your doctor makes. Therefore, it may be helpful to have another set of ears in the room, such as a friend or family member who can listen and take notes.
During the medical history, your doctor will be interested in knowing about the type of pain you are experiencing, including location and pattern (whether it involves both knees or hips or only joints on one side), how it affects your mobility and lifestyle, and whether it is affecting your sleep and causing fatigue. Your doctor will want to know about any other medical problems you have. Some medical problems tend to occur along with RA and may be suggestive of the disease. Additionally, it is important to give your doctor a complete list of any medications and vitamins/supplements you are currently taking.
In addition to all of this information, your doctor will also ask about your family medical history. Since there is a hereditary component to RA, information about any close relative with RA (or any other autoimmune disease) may help your doctor get a complete picture of your risk.
A key part of the assessment during your first visit to your doctor will be the physical exam. In addition to checking general health parameters, including blood pressure, pulse rate, heart and lung function, your doctor will evaluate your joints in great detail. He or she will pay particular attention to function, swelling, and pain. If you have RA, the physical exam will also help your doctor determine the severity of your disease, which will help guide treatment decisions.
Laboratory testing is an important part of forming a complete picture to help determine your diagnosis. There are certain substances that tend to be present in the blood of patients with RA or elevations of common components of blood that are suggestive of inflammatory disease. Laboratory tests for RA commonly look at:
- Rheumatoid factor (RF)
- Anti-citrullinated protein antibodies (ACPA) (including anti-cyclic citrullinated peptide [anti-CCP] and anti-mutated citrullinated vimentin [MCV] antibody tests)
- Erythrocyte sedimentation rate (ESR)
- C-reactive protein (CRP)
- Antinuclear antibody (ANA)
- Complete blood count (CBC)
Your doctor may have x-rays taken of symptomatic joints. X-rays can reveal certain signs of joint involvement (inflammation) and damage (bone erosion) that are indicative of RA. Other imaging tests that may be useful in diagnosis of RA include magnetic resonance imaging (MRI) and ultrasound.