Definition for chronic renal disease

Chronic renal failure (CRF, or "chronic kidney failure", CKF, or "chronic kidney disease", CKD) is a slowly progressive loss of renal function over a period of months or years and defined as an abnormally low glomerular filtration rate, which is usually determined indirectly by the creatinine level in blood serum.

CRF that leads to severe illness and requires some form of renal replacement therapy (such as dialysis) is called end-stage renal disease (ESRD).