Hi @wv54, from what I've read, in Cecil and Goldman's Textbook of Medicine, PMR is an autoimmune disorder with certain genetic markers that usually strikes people over 50 at a rate of 52.5 per 100,000 people annually, women more than men, and Caucasians, especially those of Northern European Ancestry. My ancestry is about 75% southern European, but a maternal aunt also had PMR and GCA, as I do. (About 30% of those with PMR develop GCA). My PMR started a couple of days after I injured my ankle, my aunt's started after she hurt her back. Bayord Horton and other doctors at the Mayo Clinic did groundbreaking work on GCA and performed the first temporal artery biopsies, which became the diagnostic tools for identifying GCA. In the 1950s, Horton found that steroids could be used to manage the symptoms. I am grateful for this as my life would have been hell without prednisone. I always exercised, ate plant based diet, etc. and was almost fanatical in pursuing a healthy lifestyle, so PMR and GCA were humbling shocks. I learned I may have some control, but not total control, over my body.