What is Chronic Kidney Disease (Definition)?

Chronic kidney disease is the final common pathway in many different diseases that affect the kidney. Common causes include inflammations of the glomeruli (glomerulonephritis) and of the renal calices (pyelonephritis) as well as chronic high blood pressure (hypertension) and diabetes mellitus.

Chronic kidney disease is characterised by a progressive loss of renal function. Depending on the activity of the underlying disease process, renal function may be lost slowly or rapidly. The end stage of kidney failure may develop over many years or within only a few months.

In general, the functional units of the kidney – the nephrons – cannot recover after injury; i.e., they are either active or functionally dead. However, because there are so many nephrons, the kidneys have a large functional reserve. The body can cope with the loss of one kidney as well as a considerable accumulation of waste products.

Stages of chronic kidney disease

Defined by the level of the kidney function (glomerular filtration rate, GFR), there are five stages of chronic kidney disease (according to NKF-KDOQI Guidelines [1]). Stage 1 (GFR < 90 ml/min/1.73 m2) is the earliest, while stage 5 (GFR < 15 ml/min/1.73 m2) represents overt kidney failure. This stage is also called end-stage kidney disease (ESKD) or end-stage renal disease (ESRD). At this point, less than 15 % of the kidney tissue is working and dialysis is necessary for survival.

Stages of chronic kidney disease according to NKF-KDOQI Guidelines [1]

Did you know...?

  • Diabetes and high blood pressure cause about 70 % of kidney failure cases.

  • Heart disease is the major cause of death for all people with CKD.

  • About one third of people with diabetes will get chronic kidney disease.

  • High blood pressure is both a cause and a complication of chronic kidney disease, because damaged kidneys are less able to help control blood pressure.

Content last updated
  1. KDOQI Clinical Practice Guidelines for Chronic Kidney Disease: Evaluation, Classification and Stratification. Am J Kidney Dis 2002; 39 (Suppl 1): 1-222. http://www.kidney.org/professionals/KDOQI/guidelines_ckd/p4_class_g1.htm (last visited 30.03.2010)
  2. Fauci A, Braunwald E, Kasper DL et al.: Harrison´s Principles of Internal Medicine, 17th Edition, 2008