I have been suffering from daily headaches for many many years now. I recently had a brain scan and it was good results, I also had xray on my neck and it showed up artrites in the neck, Is it still possible that there could be something more serious wrong like a tumour of some type, is there any othe tests I could get, I take strong medication but feel I am becoming immune to it and I have been taking it so long now, any advice or help would be greatly appreciated