not extremely knowledgeable in this area - but - i would assume it's unrelated to POTS :[ Might be related to another chronic or comorbid condition though!

i have one, i used to have hyperthyroidism so it's probably from that. now i have hypothyroid antibodies, but they aren't active and my nodule is benign. they told me to get a thyroid ultrasound every year to keep an eye on it, though if they didn't get you a blood test to check all three of your tsh, t3, and t4 levels, then i would recommend starting with requesting that! usually when doctors check your thyroid, they only order a tsh test (thyroid stimulating hormone). but t3 and t4 are the hormones that your thyroid actually produces, so those levels are more likely to give you important information. endocrinologists are the doctors that treat thyroid stuff, so if you get those levels checked and anything is off, that's who you would want to get referred to. it might be a good idea to see one either way though so they can keep an eye on that nodule. i hope you get everything figured out!!

I have a nodule in my lung. It's been there for years.

I had one back in 2009, it was benign but had it removed along with half my thyroid. Somehow the remaining half works well enough, but I still sometimes wonder if it is part of my sluggishness and not all my ME/CFS or Fibro!