Thank you for this discussion. I feel right in there. My GFR started deteriorating in 2014. I took lithium for 30 years, but that was not the cause according to my nephrologist. I have Polycystic Kidney Disease as well as Nephrogenic Diabetes Isipidus. This was not known until I saw a Nephrologist. My GFR continued to go down, slightly but was stable (GRF 32-35 range) over the next 9 years. Very recently my GFR dropped to 26. I drink plain water, watch my salt, eat a low-protein diet with very little meat am not overweight (133 lbs.), do not have high blood pressure, and am on 2 medications that do not affect the kidneys. I have an appointment at Mayo Clinic this month. All my other bloodwork is perfect. Nothing out of sorts, potassium, sodium, CO2, cholesterol..all normal, actually very good. I am not diabetic (sugar). I am putting this mystery in the hands of the specialists at Mayo since my Nephrologist is not concerned and keeps telling me I'll live to 100. I understand he's trying to be positive but I'm moving up the chain of specialists.