What is Kidney Disease?
Kidney disease describes a variety of disease and disorders that affect the kidneys. Most disease of the kidney attack the filtering units of the kidneys—the nephrons—and damage their ability to eliminate wastes and excess fluids.
Chronic kidney disease (CKD) is defined as the presence of kidney damage, or a decreased level of kidney function, for a period of three months or more. CKD can be divided into five stages, depending on how severe the damage is to the kidneys, or the level of decrease in kidney function.
Usually, kidney disease starts slowly and silently, and progresses over a number of years. Not everyone progresses from Stage 1 to Stage 5. Stage 5 is also known as End-Stage Renal Disease (ESRD). It may also be called end-stage renal failure. It is important to remember that end-stage refers to the end of your kidney function (your kidneys are working at less than 15% of normal), not the end of your life. To sustain life at this stage, dialysis or kidney transplantation is needed.
When the kidneys fail, wastes and fluids accumulate in your body and you need dialysis treatments (to clean your blood either by machine or in your abdomen), or a kidney transplant. Dialysis and kidney transplantation are known as renal replacement therapies (RRT) because they attempt to “replace” the normal functioning of the kidneys.
Sometimes kidney failure occurs rapidly and this is called acute kidney failure. This may be a result of injury, infection, or other causes. For acute kidney failure, dialysis treatment may be urgently needed for a period of time, but kidney function often recovers.
Adapted from NKF, K/DOQI Clinical Practice Guidelines for chronic kidney disease: evaluation,
classification and stratification. Am J Kidney Dis 2002; 39 [Supp 1]: S19