Rheumatic diseases are chronic diseases that affect the skin, bones, joint structures and muscles, usually causing inflammation and pain. Although rheumatic diseases take many forms, many have a common origin: the body's immune system mistakes its own cells for harmful foreign agents and attacks them.GoutLupusBursitisOsteoporosisRheumatoid arthritisPsoriatic arthritisTendonitisCarpal tunnel syndromePaget's disease.