Acute Kidney Failure

(Acute Kidney Injury)

Reviewed/Revised Jun 2023
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Your kidneys are 2 bean-shaped organs that produce urine. They’re about the size of your fist and are in the back of your abdomen, near your spine. Kidneys balance your body’s water and mineral levels and filter waste out of your blood.

What is acute kidney failure?

An acute problem is one that has just started and probably won't last too long. So, acute kidney failure is when one or both of your kidneys suddenly stop working for a few days or weeks. If your kidneys stop working for a long time, you have chronic kidney disease.

Doctors now use the term "acute kidney injury" to refer to acute kidney failure. But kidney failure is still the term most people know.

  • Damage to one kidney doesn't cause major problems as long as your other kidney works—both of your kidneys need to stop working for you to have serious problems

  • You may have swelling of your feet, ankles, or face, feel sick and tired, itch all over your body, have difficulty breathing, or urinate (pee) less than usual

  • Acute kidney failure can lead to serious problems, such as heart failure

  • You may need kidney dialysis

The Urinary Tract

What causes acute kidney failure?

Acute kidney failure can be caused by:

  • Not enough blood getting to your kidneys

  • Something that blocks urine from draining out of your kidneys

  • Certain kidney diseases

  • Certain drugs or poisons

Your kidneys need a lot of blood. Your kidneys may not get enough blood if you have a lot of bleeding, have gotten very dehydrated, or your heart isn't pumping enough blood.

If a cancer or a kidney stone blocks the flow of urine, pressure builds up in the kidney. If the pressure stays high for a long time, your kidneys will be damaged.

Many drugs and other substances can damage your kidneys, for example:

  • Some antibiotics

  • Contrast agents used for certain x-rays

Contrast agents are liquids given by vein that make blood vessels and organs easier to see on x-rays.

Doctors often can’t find a cause for a person's acute kidney failure.

What are the symptoms of acute kidney failure?

Your symptoms depend on:

  • How badly your kidney is injured

  • What caused your acute kidney failure

  • How quickly your kidney problems are getting worse

First, you may have symptoms that include:

  • Weight gain

  • Swelling in your feet and ankles

  • Puffiness in your face and hands

  • Urinating less or not at all—most healthy adults urinate between 3 cups and 2 quarts of urine per day

Later symptoms:

  • Feeling sick to your stomach, tired, and less hungry

  • Trouble focusing

  • Itchiness or rashes

You also may have symptoms of the problem that caused your kidney failure.

How can doctors tell if I have acute kidney failure?

Your doctor will do:

How do doctors treat acute kidney failure?

Doctors treat the problem that is causing your acute kidney failure. Your doctor may also:

  • Put you on a special diet that limits how much fluid, salt, phosphorus, and potassium you take in

  • Have you weigh yourself each day to tell whether you're retaining fluid

  • Give you medicine to balance the potassium or phosphorus levels in your blood

  • Put you on dialysis to help remove waste and excess water from your blood

Some kidney injuries are severe and life-threatening, and need to be treated in a special care unit in the hospital. You may need surgery, for example, if your kidneys and urine flow are blocked.

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