Rheumatism is a broad term that refers to various conditions causing chronic pain and inflammation in the joints, muscles, and connective tissues. It is often associated with autoimmune disorders like rheumatoid arthritis (RA), lupus, ankylosing spondylitis, and psoriatic arthritis. Some forms of rheumatism, like osteoarthritis, are due to wear and tear, while others result from an overactive immune system attacking the body’s own tissues.