Ganglion, there's a word I haven't heard in about 15 yrs.
I used to get one on my left hand, on and off for years.
No one had any answers for me.
Coincidentally, I gave up wheat and gluten for other reasons and
to my surprise, the ganglion went on its merry way.
I haven't had one since.
I'm not sure if the two are related but as it's a pocket of fluid, and as fluid comes from your body's response to an irritant, it would make some sense to me that the ganglion was a result of my intolerance to wheat and gluten at the time.