Chronic kidney disease is a condition in which the kidneys are not working correctly. It is caused by damage to tiny structures within the kidneys called nephrons (pronounced nef-RONS). About 20 million Americans have chronic kidney disease and 500,000 individuals have end-stage renal disease. In the early stages, chronic kidney disease does not cause symptoms; therefore, most people don’t know they have the condition.
The kidneys are bean-shaped organs located in the lower back just below the rib cage. Each kidney is about the size of a fist. The two kidneys filter blood, catch needed substances, return them to the circulation, and dispose of wastes in the urine. If the kidneys don’t filter properly, wastes build up in the blood. The kidneys also maintain the balance of water in the body and release hormones. These hormones keep the bones strong, control blood pressure, and help the body make red blood cells. If your kidneys stop working, your bones may become weak, your blood pressure may increase, and your red blood cell count may decrease.
Anatomy of the Kidneys
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Chronic kidney disease is a progressive condition. Doctors use stages to describe how serious it is. The stage is based on the glomerular filtration rate (GFR).
Glomerular Filtration Rate (GFR)
||Over 90 mL/min (normal)
||60 to 89 mL/min (mild decrease)
||30 to 59 mL/min (moderate decrease)
||15 to 29 mL/min (severe decrease)
||under 15 mL/min (kidney failure or end-stage renal disease)
The two most common causes of chronic kidney disease are diabetes and hypertension.
occur when the body doesn’t process the sugar in the blood well. The amount of sugar (also called glucose) in the blood increases. High blood glucose damages the kidneys, the heart, blood vessels, and eyes.
(high blood pressure) occurs when there is high pressure within the arteries of the body. Hypertension damages the kidneys. Chronic kidney disease can also cause hypertension.
Other conditions that can cause chronic kidney disease include:
Inherited diseases, such as
polycystic kidney disease
(a condition that causes cysts to form in the kidneys)
Diseases of the immune system, such as
, tumors, or in men, an
, causing obstructive kidney diseases
urinary tract infections
- Prolonged use of medications, such as ibuprofen, aspirin, phenacetin
- Bilateral renal artery stenosis
- Tubular interstitial nephritis