There are no specific tests to completely confirm or eliminate the diagnosis of rheumatoid arthritis.

Your doctor may begin to suspect rheumatoid arthritis after taking a careful history of your symptoms. A physical exam will be done.

According to The American College of Rheumatology, if you have four of the seven symptoms listed below for more than 6 weeks you are considered to have rheumatoid arthritis:

  • Morning stiffness that lasts over an hour
  • Arthritis in at least three joints
  • Arthritis of the joints of the hand
  • Arthritis on both sides of the body (for example, involving both hands or both feet)
  • A positive blood test for rheumatoid factor (RF)
  • Presence of lumps under the skin, called rheumatoid nodules
  • X-rays that show signs of rheumatoid arthritis affecting the joints

Testing

If there are any questions about the diagnosis, your doctor may recommend other tests to confirm the diagnosis or to evaluate whether your internal organs are also involved. Such tests may include the following:

Blood tests —A number of blood tests can point to the presence of an autoimmune disorder. These include:

  • Rheumatoid factor
  • Anti citrullinated peptide antibody (anti cpp)
  • Erythrocyte sedimentation rate
  • Antinuclear antibody
  • C-reactive protein

Imaging tests —Imaging tests may be used to visualize the internal organs, in order to see whether rheumatoid arthritis has affected them. Specific areas of the body to be examined with imaging tests may be chosen based on your symptoms. Imaging tests may include:

Arthrocentesis —Removing some joint fluid for laboratory exam may reveal the presence of white blood cells, crystals, or bacteria. This test is most commonly used to exclude other causes of arthritis.