What are the 5 stages of kidney failure?

The progression of kidney failure is typically classified into five stages based on the glomerular filtration rate (GFR), which measures how effectively the kidneys are filtering waste from the blood. These stages are:

1. Stage 1: Kidney damage with normal or high GFR (GFR > 90 mL/min)
2. Stage 2: Mild reduction in GFR (GFR 60–89 mL/min)
3. Stage 3: Moderate reduction in GFR (GFR 30-59 mL/min)
4. Stage 4: Severe reduction in GFR (GFR 15–29 mL/min)
5. Stage 5: Kidney failure or end-stage renal disease (GFR < 15 mL/min)

In stage 5, the kidneys are functioning at less than 15% of their normal capacity, which means they are unable to effectively filter waste and excess fluids from the blood. At this stage, patients typically require dialysis or a kidney transplant to maintain their health and survival.