Chronic renal failure is a gradual and progressive loss of the ability of the kidneys to excrete wastes, concentrate urine,
and conserve electrolytes.Alternative names are Kidney failure - chronic;
Renal failure - chronic; Chronic renal insufficiency; CRF; Chronic kidney failure. It most often results from any disease that causes gradual loss of kidney function. It can range from mild dysfunction to severe kidney failure . Progression may continue to end-stage renal disease.