Arthritis is defined as chronic joint inflammation and cartilage degeneration. The most common type of arthritis is osteoarthritis, which has a strong genetic component and involves painful and progressive loss of surface cartilage. Other common forms of arthritis include inflammatory or autoimmune (i.e. rheumatoid, lupus, psoriatic), gout and pseudo-gout, and septic or infectious arthritis. Common Arthritis symptoms include night pain, reduced range of motion, pain in external rotation and pain after prolonged sitting. The hallmarks of osteoarthritis include radiographic signs such as asymmetric cartilage loss, bone spur formation and cyst formation, with other indicators including progressive stiffness and deformity of the joint. Arthritis is diagnosed by combining clinical symptoms (pain, stiffness, swelling, deformity) with radiographic (x-ray) findings (joint space loss, bone spur formation, cysts).