Unfortunately no one knows what causes it. If you have been on these sites for any length of time you will find that everyone has a different reason for why they think they contracted the disease. I think thats true with many auto immune diseases. I do not believe its just UK healthcare. A google search of causes of PMR you will find its believed to be genetics and environmental factors. Thats about as close as research has gotten. They did find that corticosteroids help with the symptoms. That has become about the only treatment that works. The treatment then becomes worse than the disease. If you have a good Doctor that runs all the testing to make sure its not something else then that is about as close as you can get. I may be genetically predisposed to the disease but I also think stress and covid vaccine helped set it off.