Well at least you should think yourself lucky - I still don't know exactly what's wrong with me after 3 years of various tests and appointments and X-Rays. I just presume I've been given tablets to placate me, and to support the NHS from prescription costs. The best 'diagnosis' i've had was polyarthralgia, which is as much use as a chocolate fireguard. I could tell you that a lot of my joint hurt without a degree in medicine. C'est la vie.