One way a doctor can diagnose RA is by taking a full medical history and hearing the patient’s symptoms. Among the common signs of RA are morning stiffness, three or more painful joints, involvement of both sides of the body and subcutaneous nodules.
Several blood tests can help diagnose RA by detecting inflammation and antibodies. They can also help predict severity and complications of the disease. These tests include Rheumatoid Factor, Erythrocyte Sedimentation Rate, C-Reactive Protein and Anti-CCP Antibody.
While X-rays aren’t able to detect early RA because they can’t show images of soft tissue, they can capture the progression of joint damage over time. Ultrasound, MRI and dexa scans may also be used to provide more information about changes in a person's body.
Several other conditions mimic the symptoms of RA. Some are similar diseases, such as psoriatic arthritis, which is also an autoimmune disease that attacks the joints. Gout and osteoarthritis can sometimes be confused for RA as well, but they are very different conditions.