The gradual loss of the kidneys' ability to work. Also called chronic kidney disease.

The kidneys filter waste and excess fluids from the blood. The waste and fluids leave the body in the urine. In chronic renal failure, the kidneys slowly stop working. As kidneys fail, waste builds up. The waste buildup can affect almost every part of the body.

Symptoms come on slowly. Depending on how serious kidney failure is, symptoms can include loss of appetite, sleep problems, high blood pressure, swelling, muscle cramps and shortness of breath.

Medicines help manage symptoms such as high blood pressure and swelling. As kidney failure gets worse, a dialysis machine may be needed to filter the blood. Or a transplant may be needed.