Thanks for your reply. I’m glad your doctors are doing the tests needed to help you. I don’t know if I’ve had a Cystatin C GFR test. Test results come in a portal that’s hard to navigate, but I’ll look again. I’ve wondered if low blood pressure could be the cause. My BP is all over the place. The bottom number is often too low, but the top one is always okay or too high, and I have no symptoms like dizziness. I can’t imagine how low it goes when I’m sleeping. I don’t think there’s a way to raise it is there? I do moderate cardio at least 40 minutes most days. Neither my primary doctor or the kidney doctor seem interested in finding out what’s wrong. I wasn’t concerned when the GFR was over 60, but except for one over 60 reading, it’s gone down consistently for years, and within the last few years it’s dropping fast. Maybe there’s just nothing they can do. I’m 78 and shrinking. I read shrinking kidneys can cause this too. It just doesn’t seem like we should have to guess or figure out what’s wrong on our own.