Overview

Acute kidney injury happens when the kidneys suddenly can't filter waste products from the blood. When the kidneys can't filter wastes, harmful levels of wastes may build up. The blood's chemical makeup may get out of balance.

Acute kidney injury used to be called acute kidney failure. Acute kidney injury is most common in people who are in the hospital, mostly in people who need intensive care.

Acute kidney injury ranges from mild to severe. If severe, ongoing and not treated, it can be fatal. But it also can be reversed. People in otherwise good health may get back typical or nearly typical use of their kidneys.

Symptoms

Symptoms of acute kidney injury may include:

  • Less urine output.
  • Fluid buildup, which can cause shortness of breath and swelling in the legs, ankles or feet.
  • Tiredness.
  • Confusion or fogginess.
  • Nausea.
  • Pain in the belly or in the side below the rib cage.
  • Weakness.
  • Irregular heartbeat.
  • Itching.
  • Loss of appetite.
  • Chest pain or pressure.
  • Seizures or coma in severe cases.

Sometimes acute kidney injury causes no symptoms. Then it may be found through lab tests done for something else.

When to see a doctor

See your healthcare professional right away or seek emergency care if you have symptoms of acute kidney injury.

Causes

Acute kidney injury can happen when:

  • You have a condition that slows blood flow to your kidneys.
  • You have damage to your kidneys.
  • Your kidneys' urine drainage tubes, called ureters, get blocked.

Slowed blood flow to the kidneys

Conditions that may slow blood flow to the kidneys and lead to kidney injury include:

  • Loss of too much body fluid, called dehydration.
  • Infection with or without sepsis or septic shock.
  • Medicines such as aspirin, ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve).
  • Blood or fluid loss.
  • Severe low blood pressure from blood pressure medicines.
  • Heart attack.
  • Heart failure or heart disease.
  • Liver cirrhosis or failure.
  • Bad allergic reaction, called anaphylaxis.
  • Bad burns.

Damage to the kidneys

The following may damage the kidneys and lead to acute kidney injury:

  • Swelling and irritation, called inflammation, of the tiny filters in the kidneys. This is called glomerulonephritis (gloe-mer-u-loe-nuh-FRY-tis).
  • Medicines, such as certain chemotherapy drugs, antibiotics and dyes used during imaging tests.
  • Infection, such as with the virus that causes coronavirus disease 2019 (COVID-19).
  • Toxins, such as alcohol, heavy metals and cocaine.
  • An immune system condition called lupus that causes glomerulonephritis.
  • Blood clots in the veins and arteries in and around the kidneys.
  • Cholesterol deposits that block blood flow in the kidneys.
  • A condition that results from red blood cells being destroyed too early, called hemolytic uremic syndrome.
  • A group of rare diseases affecting the skin and connective tissues called scleroderma.
  • A rare blood disorder called thrombotic thrombocytopenic purpura.
  • Muscle tissue breakdown, called rhabdomyolysis. The toxins from the muscle being destroyed leads to kidney damage.
  • Breakdown of tumor cells called tumor lysis syndrome. This leads to the release of toxins that can injure the kidneys.

Urine blockage in the kidneys

Conditions that keep urine from leaving the body are called urinary obstruction. These can lead to acute kidney injury. They include:

  • Kidney stones.
  • Enlarged prostate.
  • Blood clots in the urinary tract.
  • Bladder cancer.
  • Prostate cancer.
  • Cervical cancer.
  • Colon cancer.
  • Growth pushing on the ureters.
  • Nerve damage of the nerves that control the bladder.

Risk factors

Acute kidney injury almost always is linked to another medical condition or event. Conditions that can increase your risk of acute kidney injury include:

  • Ongoing kidney disease, also called chronic kidney disease.
  • Older age, but it does happen to children.
  • Being in the hospital, most often for a serious condition that needs intensive care.
  • Blockages in the blood vessels in your arms or legs, called peripheral artery disease.
  • Diabetes, especially if it's not controlled.
  • High blood pressure.
  • Heart failure.
  • Liver diseases.
  • Certain cancers and their treatments.

Complications

Complications of acute kidney injury may include:

  • Fluid buildup. A buildup of fluid in your lungs can cause shortness of breath.
  • Chest pain. The lining that covers your heart, called the pericardium, can get inflamed. This can cause chest pain.
  • Muscle weakness. This can result from the body's fluids and minerals in the blood called electrolytes being out of balance.
  • Permanent kidney damage. Sometimes, acute kidney injury causes lifelong loss of the use of the kidneys, called end-stage renal disease. People with end-stage renal disease need either lifelong treatments to remove waste from the body, called dialysis, or a kidney transplant to survive.
  • Death. Acute kidney injury can cause the kidneys to stop working.

Prevention

You might cut your risk of acute kidney injury by taking care of your kidneys. Try to:

  • Get treated quickly for bad infections.

  • Work with your healthcare team to manage kidney and other ongoing conditions. Kidney disease, diabetes or high blood pressure increases your risk of acute kidney injury. If you have one of these, do what your healthcare team tells you to manage your condition.

    If you have risk factors for kidney disease, check with your healthcare team to be sure that prescription medicines you take are safe for your kidneys.

  • Read labels when taking pain medicines available without a prescription. Do what the label says when taking medicines such as aspirin, acetaminophen (Tylenol, others), ibuprofen (Advil, Motrin IB, others) and naproxen sodium (Aleve). Taking too much of these medicines may increase your risk of kidney injury. This is especially true if you already have kidney disease, diabetes or high blood pressure.
  • Live a healthy lifestyle. Be active and eat a healthy, balanced diet. If you drink alcohol, drink only in moderation.
By Mayo Clinic Staff