. . .it IS a very common disease. Approximately one in fifteen people will experience some degree of peripheral neuropathy in their lifetimes.

There are at least 300 possible causes, including the many hereditary ones--though coffee is not usually listed among them (not that caffeine can't make you jittery, but the EMG results do suggest there is something going on).

I concur with the advice to check out the Useful Websites section here, and one good place to get an idea of the possibilities for cause--and it might be a good idea to get a consult, as some of those causes are harbingers of worse stuff, but, conversely, some are treatable--is the Algorithm for the Evaluation of Peripheral Neuropathy, AKA the Poncelet Protocols:

An Algorithm for the Evaluation of Peripheral Neuropathy | AAFP

And, if you want to get some feedback from online support groups which have people with similar stories, check out the Western Neuropathy Association website at HOME :: Western Neuropathy Association. Full disclosure--I am on the Board of Directors there.

That is more common that I thought, but I imagine that number would probably be cut in half if you eliminate those whose cause is diabetes.

Thank you for those links. The diagnostic one was especially interesting, until the flowchart led me to a place where the table was not available (table 2). Nevertheless, that was convincing enough to me that it likely is a good idea to have at least an initial consultation, and see what happens from there.

Thank you for both links, definitely plenty to read there (as well as here).

If I learn anything, or if my symptoms progress, I will update this thread in the future, in case it ever helps anyone else.