I haven't had that experience, but I usually do longer fasts. My go to for this would be electrolyte levels, which can vary heavily depending on water intake,

I haven't had that experience, but I usually do longer fasts. My go to for this would be electrolyte levels, which can vary heavily depending on water intake, diet, exercise, supplementation, etc. Here's some journal articles I found based on a quick search. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1364615/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1364615/ https://pubmed.ncbi.nlm.nih.gov/8777833/ https://pubmed.ncbi.nlm.nih.gov/8777833/ https://link.springer.com/article/10.1007/s002280050682 https://link.springer.com/article/10.1007/s002280050682 Be interested to hear if something in one of those pops out at you.