Serum creatinine of 2 mg means glomerular filtration rate (GFR) of 43.5 ml per minute in your case. Normal GFR is 100-120 ml per minute. Stage 1 disease is GFR more than 90 ml; Stage 2 disease is GFR of 60-90 ml; Stage 3 disease is when GFR is 30-60 ml; Stage 4 disease is when the GFR level is at 15-30 ml and finally Stage 5 is GFR less than 15 ml per minute. Stage 5 is called kidney failure. Dialysis and kidney transplantation are required for stage 5 disease.