The kidneys perform several important functions, including:

  • Filtering blood to remove waste products, expelling waste from the body as urine and returning water and chemicals back to the body as necessary.
  • Regulating blood pressure by releasing several hormones.
  • Stimulating red blood cell production by releasing the hormone erythropoietin.

When the kidneys stop working, this is referred to as end-stage renal disease. Toxic waste products accumulate in the body and the patient needs either dialysis or a kidney transplant to survive. Neither of these options is a cure for kidney failure, but a transplant offers the best prospects if the transplanted kidney functions successfully.