115! UGH!! no wonder you were hyponatremic, @MeSci. I feel bad when my sodium gets a few points low, in the mid 130's. To update, after I started on pot. bicarb last year, my POTS symptoms slowly resolved. I stayed on it for almost a year, and now am mostly off of it. If I start getting sore muscles for no reason, I do another round of it. But I have not caught myself having a low BP since I started taking it - I stay up above 90/60 pretty much all the time. It definitely fixed something. I still have some level of OI, etc. esp. when I am bending down and standing back up. The terrible near blackouts have mostly resolved - I might have one now and then when I am actually dehydrated. I did go low on potassium at one point while taking it, so I still need extra potassium (currently seems to be 10-20 MEQ, depending on what my bloodwork shows). I have not stopped needing extra salt either, though my need for it is generally lower than last year. I had myself tested for Sjogrens and am negative, though I still have persistent dry eyes. For some reason, while I was taking p. bicarb, my ears started making wax again, though. My mouth is not nearly as dry & burning when I have sufficient bicarb. Dry mouth is another symptom for me that I need bicarb. I guess that's all I can say about it. It has been good stuff for me.