Rheumatic diseases are painful conditions usually caused by inflammation, swelling, and pain in the joints or muscles.
Some rheumatic diseases like osteoarthritis are the result of "wear and tear" to the joints. Other rheumatic diseases, such as rheumatoid arthritis, happen when the immune system becomes hyperactive; the immune system attacks the linings of joints, causing joint pain, swelling, and destruction.
Almost any joint can be affected in rheumatic disease. There are more than 100 rheumatic diseases but we'll focus on some of the common types.