I’ve read of those, too. I think they are called “hot” nodules because they can produce hyperthyroidism all on their lonesome, without being under the control of the pituitary system. But I think the uptake test would show hyperthyroidism, if this were a hot nodule. I’m not sure, though. Well, I hope they can figure out what is causing your mom these symptoms. Whatever the cause, they are not comfortable to have. Good luck.
Bobbi