Diagnosis

During the physical exam, doctors check your joints for swelling, redness and warmth. They'll also want to see how well you can move your joints.

Laboratory tests

The analysis of different types of body fluids can help pinpoint the type of arthritis you may have. Fluids commonly analyzed include blood, urine and joint fluid. To obtain a sample of joint fluid, doctors cleanse and numb the area before inserting a needle in the joint space to withdraw some fluid.

Imaging

These types of tests can detect problems within the joint that may be causing your symptoms. Examples include:

• X-rays. Using low levels of radiation to visualize bone, X-rays can show cartilage loss, bone damage and bone spurs. X-rays may not reveal early arthritic damage, but they are often used to track progression of the disease.
• Computerized tomography (CT). CT scanners take X-rays from many different angles and combine the information to create cross-sectional views of internal structures. CTs can visualize both bone and the surrounding soft tissues.
• Magnetic resonance imaging (MRI). Combining radio waves with a strong magnetic field, MRIs can produce more-detailed cross-sectional images of soft tissues such as cartilage, tendons and ligaments.
• Ultrasound. This technology uses high-frequency sound waves to image soft tissues, cartilage and fluid-containing structures near the joints (bursae). Ultrasound is also used to guide needle placement for removing joint fluid or injecting medications into the joint.