I believe channelopathies could be involved indeed. Maybe as a secondary cause, something that got damaged because of another imbalance or deficiency? I didn't have any of these symptoms before, they only appeared last year after the bleach, so I think it must be something else that is throwing everything out of balance. I know there's something going on with potassium in my case, as since this worsening happened I've had intense cravings of specific foods, that I could not explain, but later realized were all foods that are high on potassium (potatoes and bananas, mostly).
If I don't eat any of those during the day, I start getting a slight dizziness and my heart does all kinds of weird jolts and jumps. In fact, it's happening today. I first thought about potassium when Quantum commented this on my case summary thread:
I also have exercise intolerance. When I do sports in the evening, I used to wake up the following night in hypotension and tachycardia. Hopefully, I found that taking enough potassium ( around 16 mEq) and magnesium after sports spare me that awful discomfort. However, it is not clear yet as to why potassium helps me, both in POIS and after exercise.
I am happy, IronFeather, that my comment helped you find something that improves your quality of life!
In my case, I have found some info about why potassium helps me, but I do not understand the complete picture yet ( my health is a 10000 pieces puzzle, like it is for many other POISers...) I am still using potassium but will have to refine my protocol. Usually, low potassium causes high blood pressure, but during POIS, and in POIS-like symptoms after sport, I have low blood pressure... so, I often have to take sodium ( salt) too, with my potassium, to keep normal blood pressure. Sodium and potassium have a reverse relationship - when you raise one, you lower the other. So I have to take only the potassium I need, not too much, to not lower my blood pressure too much, and also take some sodium if blood pressure gets too low. I will have to figure out if I also have a defect in some sodium channels. I will dig my genome data about this.