What Causes Constant Pain All Over The Body?

I am achy. I have ostio-arthritis and Mobic for it. O recently had a bout of sciatica in my hip and was given a prednisone pack. (6days) I was told to leave the Mobic off until I finished the pack and did, resuming it the next day. I have been taking the Mobic again since March 31 and I ache, pretty much all over, but particularly in my legs. Any advice?