Acute Kidney Failure Health Center

Kidneys are bean-shaped organs, each about the size of a fist. The kidneys are located near the middle of the back just below the rib cage and are sophisticated reprocessing machines. Each day, an person's kidneys process about 200 quarts of blood to sift out about 2 quarts of waste products and excess water. These wastes and water become urine which then exits the body through urination. Wastes that are present in our bloodstream, come from the normal breakdown of active tissues, such as muscles and from food sources. The body needs food for energy and internal repairs. Once the body has taken all it needs from the foods we ingest, wastes are sent to the blood. If our kidneys did not remove them, these wastes would then build up in the blood and go on to damage the body.

Acute kidney failure is a rapid loss the kidneys' ability to filter the blood and maintain the body's fluid and electrolyte balance. This can be caused from a variety of factors including an accident or injury, poison or trauma.

Acute kidney failure occurs in about three to seven percent of the 37 million yearly admissions to United States hospitals, or about 1 to 2.6 million people. 

It usually occurs in three settings: Loss of blood flow to the kidneys (blood loss, low blood pressure from heart failure, hardening of the renal arteries and blood clots), damage to the kidney tissue (from medications, infections, poisons), and obstruction of urine flow (enlarged prostate, urinary stones, bladder cancers, obstruction of the urethra). It is a medical emergency that can result in chronic kidney failure or death if left untreated.

Symptoms can be sudden, and are dependent on the type of kidney failure occurring. Usually, some combination of headache, fatigue, nausea, and loss of appetite is common. Irregular heartbeat, blood in the urine, seizures, swelling of the feet, and pain in the flanks may also occur.

Diagnosis is made by testing the blood and sometimes ultrasound and CT scan. Treatment is aimed at eliminating the underlying cause of kidney failure, for example, in fluid loss, restoring fluids and electrolytes; in injury, removing the offending drug; in blockage, removing the blockage. 

Reviewed by: 
Review Date: 
August 20, 2012
Last Updated:
June 2, 2014