Have Had Pain And Swelling (off And On) In The

Have had pain and swelling (off and on) in the joint at the base of my left thumb for a long time and just considered it to be the starting of arthritis, but now it is getting worse and hurting almost all the time and is even more swollen and is preventing me from doing things with that hand. Have tried topical creams on it and pain meds and get some temp relief but it is very trouble some and causing much discomfort evey day. Was thinking maybe I need an injection but now I'm wondering if it is a carpal tunnel issue and not just arthritis