Rheumatoid Arthritis, which is a chronic systemic degenerative disease characterized by inflammation of the connective tissues and manifests mainly in and around peripheral joints of the body. Osteoarthritis is the most common of all the joint disorders, affecting many millions of people throughout the world. Men and women are equally affected, but the onset occurs earlier in men. In women, the incidence increases after menopause. Rheumatoid Arthritis is often classified as an autoimmune disorder, and a familial link is suspected.
Women are three times more likely to be affected than men are.
Onset of the disease usually occurs between 35 and 50 years of age, though, rarely, the disease has been also diagnosed in children. The cause of osteoarthritis is not known, but is believed to be related in some way to ageing and genetic factors. The water content of the hyaline cartilage in the joint increases, and the protein-carbohydrate molecules present in the cartilage decreases. The cartilage becomes softer and weaker, loses resilience and elasticity and sheds flakes into the joint. The shedding erodes away the cartilage and increases the friction in the joint, setting up an erosive cycle.