Creatinine is a waste product produced naturally by the muscles as they use energy. Healthy kidneys filter it from the bloodstream and excrete it through urine, maintaining balanced levels. When ...

DEAR DR. ROACH: I am a 73-year-old female. A recent blood test returned an eGFR (estimated glomerular filtration rate) of 59. My physician’s nurse told me that the test was normal. When I asked her ...