That's a good question. Sometimes I do think that the feeling of being bloated may be related to breathing too much, like having to do with the diaphragm working a lot. But it's only present when my sinuses are inflamed and I'm breathing more than usual due to the exacerbation of the air hunger. General inflammation might be a factor and I understand there may be certain markers from a medical perspective which might be worth for you to consider as well.