Which of course makes it difficult to know what to ask the doctor, which was the original question on this discussion. No point in asking my GPs anything as none of them had a clue but I suppose in hindsight I would ask the consultant, whatever kind of specialist they are, what are all the possible causes and could they please test me for them all. That did happen for me eventually over 12 or more months. And I would have been prepared with my photographs. It took a while for me to realise that describing my symptoms was useless if they couldn’t see it happening and at a morning clinic I am unlikely to go into full flare. Not being believed was demoralising and I enjoyed handing over a set of before and after photos and seeing the expression on their faces change from sceptical to interested.
True. I think the problem is that all the possible causes are not firmly established. If you paint with a board brush, you can probably say it's neuropathy, hematological, primary/genetic, auto-immune, or medication, but no list like that is comprehensive with certainty. It simply hasn't been researched enough.
I long since gave up trying to work mine out; it was just not worth it in the end. My neurologist says it is all neurological so I’m happy to go along with that since he was second person to diagnose me (I was the first,lol). I had a list of four or five things that may have triggered it but since then my daughter has developed it so I no longer have a clue.