Acute Kidney Failure

• Acute Kidney Failure Overview
• Acute Kidney Failure Causes
• Acute Kidney Failure Symptoms
• Exams and Tests
• Acute Kidney Failure Treatment
• Self-Care at Home
• Medical Treatment
• Next Steps
• Follow-up
• Prevention
• Outlook
• Support Groups and Counseling
• Synonyms and Keywords
• Authors and Editors
• Related kidney failure articles:
  Kidney Failure - on WebMD
  Kidney Failure - on MedicineNet
• Viewer Comments: Acute Kidney Failure - Symptoms

Acute Kidney Failure Overview

The kidneys are a pair of small (about the size of your fist) bean-shaped organs that lie on either side of your spine at just below your lowest ribs. They filter by-products and toxins from your blood and preserve the balance of bodily fluids and electrolytes.

• The kidneys excrete these compounds with water to make urine.
  
  
• They also eliminate excess body water while reabsorbing useful chemicals and allowing waste to pass freely into the bladder as urine.
  
  
• They allow a person to consume a variety of foods, drugs, vitamins and supplements, additives, and excess fluids without worry that toxic by-products will build up to harmful levels.
  
  
• The kidneys regulate the amount of various substances in the blood and the amount of water in the body.

Blood circulates through the kidneys for filtration.

• As the first step in filtration, the blood passes through the glomeruli, complex structures composed of tiny blood vessels entwined together. Substances present in the blood are selectively filtered across the outer linings of the tiny blood vessels and excreted with water as urine or reabsorbed into tube-like structures (tubules) for further filtration.
  
  
• The tubules continue filtering blood until all appropriate substances are reabsorbed into the blood and all the waste products are excreted.
  
  
• Once urine leaves your kidney, it travels through long, thin tubular ureters to the bladder and out your urethra during urination.
  
  
• The kidneys also help regulate blood pressure and secrete hormones that contribute to red blood cell production.

Kidney failure occurs when the kidneys partly or completely lose their ability to filter water and waste from the blood.

• The build up of toxic substances normally removed from the body by the kidneys can cause dangerous health problems.
  
  
• Acute kidney failure (also referred to as renal failure) happens rapidly.
  
  
• Mild kidney dysfunction is often called renal insufficiency.

Acute kidney failure occurs in about 5% of people who are hospitalized for any reason. It is even more common in those receiving intensive care.

Chronic kidney failure results when a disease slowly destroys your kidneys. Destruction occurs over many years, usually with no symptoms until the late stage of kidney failure. Progression may be so gradual that symptoms may not occur until kidney function is less than one-tenth of normal.