Rheumatism, in medical terms, refers to chronic pain of unknown cause in joints and the surrounding soft tissues. Rheumatic diseases refer to conditions that mainly affect joints, muscles, bones, and soft tissues around joints, such as tendons, ligaments, bursae, and fascia. For a guide on seeking medical care for common rheumatic diseases, see the relevant pages on our website: rheumatism, rheumatic arthritis, rheumatoid, rheumatoid arthritis, internal rheumatism, etc.