Diagnosis depends on the type of arthritis suspected by the doctor. Most of the time, the testing is very similar:
- No matter which type of arthritis is suspected, a patient will have a complete medical exam that includes personal, medical, and family history.
- Functional tests are often performed to determine the range of motion of the affected joint.
- Diagnosis will be helped with the use of X-rays, computerized tomography (CT) and magnetic resonance imaging (MRI).
- A blood test, called the erythrocyte sedimentation rate (ESR), can help to determine if there is inflammation in the whole body. ESR is nonspecific test and may point to many types of arthritis.
After the general tests, more specific tests may be used to help make the diagnosis:
- General blood tests are often performed and can show the presence of an infection, suggesting an infectious arthritis.
- Gout is determined by testing the uric acid level in blood.
- Pseudogout is unique in that it requires a test where some of the fluid of the joint is extracted and examined under a microscope.
- Further testing may be performed if rheumatoid arthritis is suspected. The two blood tests typically performed are called rheumatoid factor (RF) and antinuclear antibody (ANA). The tricky part of rheumatoid arthritis is that not everyone with rheumatoid arthritis has positive results from these tests.
