Hi @rolandhp, From Cecil and Goldman's Textbook of Medicine, "These disorders (PMR + GCA) are propagated by antigen-driven, cell-mediated immune mechanisms that may be associated with specific genetic markers ..." They occur more often in women than men, usually Caucasians, and to persons 50 years or older. The highest rates occur in those of Northern European ancestry. My ancestry is Southern European, and my maternal aunt had PMR + GCA. Also, my mother-in-law had these disorders and her ancestry was English and French. The onset of my symptoms came after what seemed a minor but annoying ankle injury from walking backwards too much. My aunt's symptoms came on after she hurt her back moving furniture. Usually, with autoimmune disorders, it seems there's an event that triggers the immune system to go into overdrive. I think of PMR +GCA as the beasts, lurking in the shadows, waiting for an opportunity to pounce. I just started a taper of prednisone to 7.5 mg in one dose - so far, no problems, and I'm strength training three times a week, walking /stepping at least 5 days and doing two 15 minute sessions 6 days a week on a Whole Body Vibration Exercise Machine. The pain of PMR was like nothing I ever experienced. I will never forget the incredible stiffness and being unable to move in any way without pain! All the best. Stay active, but don't overdo it, as many report problems when they do. Best wishes!