@reecie1950 Welcome to Mayo Clinic Connect. Have you sought the care of a nephrologist [kidney care specialist] yet? Decreases in eGFR can be caused by kidney disease brought on by the two main causes of high blood pressure and diabetes, or factors like genetic tendencies, lifestyle choices, etc. Basically, doctors will look at trends rather than a specific lab result, unless there is an acute situation. Also, hydration can play a big part in the test results, as can a different in the actual laboratory/equipment used to process the samples.
Ginger

Good morning. My situation is very familair to yours. July/2022 mine was 78. April 2023 it went down to 64. Very recent blood work 05/30/2023 it went down to 53. It has dropped 25 numbers in 10 months. I am righteously very worried! My Doctor did "Admit" my Kidneys are stressed, but does not seem concerned~ I go back for blood work in June with a urine test which I requested. You would think with this drastic drop, my Doctor would have requested it! I hope yours gets better. What I have been reading, many on this forum have had sudden crashes with their Kidney numbers.