Kidney failure is not defined by “creatine” levels. Clinically, kidney function is assessed using creatinine, eGFR staging, urine albumin/protein, blood pressure, imaging, and—critically—trends over time. A single creatinine threshold can be misleading because muscle mass, age, hydration, and acute vs chronic changes matter. Acute kidney injury often shows rapid rises; chronic kidney disease progresses more slowly. If creatinine is rising or eGFR is falling, medical evaluation should focus on causes such as dehydration, medications, infection, obstruction, or uncontrolled hypertension/diabetes. Early detection and structured management can slow progression substantially.