 If arthritis (inflammation of the joint) is not controlled, it can lead to irreversible joint damage.The synovial membrane or "synovium" encloses each joint and also secretes a lubricating fluid that allows different joint motions such as rolling, folding and stretching.When the synovium becomes inflamed or irritated, it increases fluid production, resulting in warmth, tenderness, and swelling in and around the joint.