A physical examination may show that fluid is collecting around the joint. The joint may be tender when it is gently pressed and may exhibit warmth and redness, more typically in infectious arthritis and autoimmune arthritis. It may be painful or difficult to rotate the jointin some directions. In certain autoimmune forms of arthritis, the joints may become deformed if the disease is not treated. Such joint deformities are the hallmarks of severe, untreated rheumatoid arthritis.
Tests vary depending on the suspected cause.
They may include blood or urine tests as well as joint X-rays . In septic arthritis, joint fluid is removed from the joint with a needle and examined for the presence of infection. See the specific types of arthritis. Arthritis Please read this Important notice .