The nephrologist actually at first could not determine an exact cause an finally pinned a possible causal on a prior Med I was on low dose for a couple years, although I can recall being somewhat low prior to taking any meds. Could be from diet or prior unawareness of being hydrated enough. Just recently another Dr felt I may not totally be in CKD for sure as he said the fact I’ve gone back up as high as 57 wasn’t normally something he’s seen and suggested I get even more diligent on food and water and see how that does. Currently fighting a bacterial infection so that lowered it but almost recovered what I lost after less than a week on antibiotic Rx.