My friend has moderate arthritis and says heat and exercise are the best things to keep it at bay.  If it gets too bad, every once in a while she will go for a cortisone shot, but she really doesn't like doing that as she says the shot itself is quite painful even though it does help.

My grandmother has terrible arthritis and she isn't able to do anything for it other than pain meds.  My Aunt also has it and she actually gets an IV every so many months.