Redness of the joints refers to redness of the skin surrounding a joint. It can often be accompanied by warmth, swelling of the joints, limited range of motion, joint stiffness, or joint pain. Redness of the joints is common in active arthritis such as rheumatoid arthritis. Redness can also develop due to injury to the joint or to the surrounding structures. Depending upon the exact cause, redness of the joints can occur in a single joint, or multiple joints in the body may be involved at one time. There are many causes of arthritis, and all are causes of joint redness. Tumors of the bone or joint lining (synovium) are very rare causes of joint symptoms, including redness.