My boyfriend has a traveling pain that moves from one joint to another, each time it moves the new place is very painful and the other places don't go away either, it even moved to his jaw, what is it?
So many things come to mind. The general categories include infection, auto immune disease, or systemic inflammatory disease. Your BF will really need to see a doctor who will need more information plus a physical exam before he/she can begin to answer your question. That question looks simple enough to answer but really is not so simple.
A rheumatologist would be your best bet.
Dr. Christina Lasich, MD