cracking sound in your joints could be because of many reasons - bone deformation, cartilage overgrowth, uric acid, and like you said arthritis. if it's painful and gets in your way of normal daily activities, go see a doctor. it could be any of the above listed problms and/or more.  
physical therapies can correct most of the joint problems. drugs are available but some cases of arthritis cannot be cured completely. however, there are medications you can take to reduce pain/keep the symptoms under control.