Unfortunately, there is no single test that can be used to definitively diagnose arthritis. Instead, diagnosis is based upon a combination of factors including medical history, physical examination, medical imaging, laboratory tests, and other tests.
The most common test used to diagnose arthritis is X-rays, which can help detect any signs of joint damage, such as narrowing of the joint space or bone spurs. Other imaging techniques, such as magnetic resonance imaging (MRI) and ultrasound, may also be used to look for signs of joint damage or inflammation.
Blood tests may also be used to detect certain forms of arthritis, such as rheumatoid arthritis (RA). The most common blood tests used to diagnose RA are the erythrocyte sedimentation rate (ESR) and the C-reactive protein (CRP) test, which measure inflammation in the body. Additionally, certain autoantibodies can be detected with blood tests, which can be used to diagnose RA.
Other tests, such as joint aspiration, may also be used to diagnose arthritis. In joint aspiration, a needle is inserted into a joint to collect samples of the joint fluid. The fluid can then be tested for the presence of certain substances, which can help identify the type of arthritis.
Finally, some doctors may also use a physical examination to help diagnose arthritis. During the physical exam, the doctor will look for signs of tenderness, swelling, and joint deformity.
Ultimately, there is no single test that can definitively diagnose arthritis, and diagnosis is based upon a combination of factors. However, X-rays, blood tests, joint aspiration, and physical examination can all be used to help diagnose arthritis.