@anniegk
@nscappa

One of the most common lab tests is an eGFR test based on your creatinine results. There is another test based on eGFR called Cystatin C which has to do with your cardiovascular system and other health measures that relate to kidney function. Both are eGFR tests that show one point in time the state of your kidney disease. There are some insurance companies that do not pay for Cystatin C which is why most docs and nephrologists order the eGFR based on creatinine that shows muscle mass. The Cystatin C test is the more accurate of the two. Similar to blood pressure, each test is one point in time and can vary for many reasons. You will find the best indicator for kidney disease function is followed by looking at the history of your values over time. It is this trend that matters most.

I am not a doctor of any kind but would suspect the rapid decrease in creatinine eGFR may be the result of hydration at the time of your test, but also could be the result of other factors as well. Check your trend and try to use Cystatin C if your insurance covers it as well.