Rhumatology is a medical field which deals with the rheumatic or osteoarticular affections (i.e. which touch bones and articulations) and their possible consequences, for example a degradation of the cartilage (osteoarthritis) or severe inflammatory problems (spondylarthritis or rhumatoid polyarthritis). In rhumatology, the rhumatoid polyarthritis is the most frequent chronic inflammatory affection rheumatic. It is caused by a disorder of the immune system which starts to attack tissues rather than to protect them (= auto-immune disease).