47 yr m. non african gfr rate was 78 (usually 95-100) creatinine 1.11. (usually .9-1.0) rbc 4.64 usually over 5. side &back tightness/ pain. next test week later drank lots & lots of water before, gfr 101 and creatinine .9 rbc 4.86. kidney problem?

High fluid intake does artificially lower serum creatinine and increase eGFR; however, your previously low numbers of serum creatinine and eGFR are just lab variations and the fact that your kidneys' response well with increased fluid intake argues against a kidney problem. In the future, when you have doubt about a blood test result, you should have it repeated under the same environment.

Be certain they are using the non-race based eGFR. The decrease in creat most likely related to your hydration and dilution of blood from hydrating. Discuss with your Dr as they will know meds u r on that can affect eGFR