Osteoarthritis (OA) is the wear and tear kind of arthritis, also known as degenerative joint disease or DJD. It is a complex disease with varied symptoms: pain, stiffness, swelling, and activity limitation. To tackle it effectively patients need different treatments for different symptoms which vary over time. The tissue that lines your joints becomes inflamed and swollen; it gets pinched between the moving bones. Once the cartilage wears away, patches of underlying bone are exposed. The bone has many nerve endings, and is very sensitive if those patches make contact. An unstable arthritic joint strains the ligaments and muscles that support it. Inflammation within these soft tissues is painful.