Inflammatory Arthritis
Inflammatory types of arthritis are characterized by their tendency to cause inflammation in joints and tendons. In inflammatory arthritis, the synovial membrane becomes swollen and inflamed, causing pain and stiffness. Chemicals released in the inflamed tissue increase blood flow to the joint, causing it to look red and feel warm to the touch. To reduce pain, patients with arthritis may favor affected joints, holding them in a fixed position. This causes the muscles surrounding the joints to stiffen and weaken and the tendons, which attach muscles to bone or to other muscles, to tighten. As a result, joints may contract or change shape and patients may eventually lose mobility. Inflammatory arthritis may be caused by autoimmune diseases in which the body’s immune system attacks its own healthy tissue. It can also be caused by crystal deposits in the joints or by infection.