Musculoskeletal symptoms are very common and may arise from joints, bones, muscles, ligaments, tendons, or bursas (see Introduction to the Biology of the Musculoskeletal System).
Common symptoms of musculoskeletal disorders include pain, weakness, stiffness, joint noises, and decreased range of motion. Inflammation may cause pain, swelling, warmth, tenderness, impaired function, and sometimes redness of the overlying skin. Inflammation can result from many different musculoskeletal disorders, such as autoimmune disorders (for example, rheumatoid arthritis) and infections. When inflammation affects a joint, fluid may accumulate inside the joint, causing pain, swelling, and decreased range of motion.