overview

Acute kidney failure occurs when your kidneys suddenly become unable to filter waste products from your blood. When your kidneys lose their filtering ability, dangerous amounts of waste products can build up and your blood chemistry can become imbalanced.

Acute kidney disease – also called acute kidney failure or acute kidney disease – develops rapidly, usually within days. Acute kidney disease is more common in people who have been hospitalized before, especially those who are seriously ill and need intensive care.

Acute kidney failure can be fatal and requires intensive treatment. However, acute kidney failure can be reversible. If you are otherwise healthy, you can return to normal or near normal kidney function.

Symptoms

Signs and symptoms of acute kidney failure can include:

Decreased urine output, although occasionally urine output remains normal
Fluid retention causing swelling in the legs, ankles or feet
shortness of breath
Fatigue
confusion
nausea
Weakness
Cardiac arrhythmia
Chest pain or pressure
Seizures or coma in severe cases
Sometimes acute kidney failure causes no signs or symptoms and is determined by laboratory tests done for another reason.

What are the causes of acute kidney failure

Acute kidney failure can occur for many reasons. Among the most common reasons are:

acute tubular necrosis (ATN)
severe or sudden dehydration
toxic kidney injury from poisons or certain medications
autoimmune kidney diseases, such as acute nephritic syndrome and interstitial nephritis
urinary tract obstruction
Reduced blood flow can damage your kidneys. The following conditions can lead to decreased blood flow to your kidneys:

low blood pressure
burns
dehydration
hemorrhage
injury
septic shock
serious illness
surgery
Certain disorders can cause clotting within your kidney’s blood vessels, and this can lead to acute kidney failure. These conditions include:

hemolytic uremic syndrome
idiopathic thrombocytopenic thrombotic purpura (ITTP)
malignant hypertension
transfusion reaction
scleroderma
Some infections, such as septicemia and acute pyelonephritis, can directly injure your kidneys.

Pregnancy can also cause complications that harm the kidneys, including placenta previa and placenta abruption.

What are the risk factors for acute kidney failure

The chances of acquiring acute kidney failure are greater if you’re an older person or if you have any of the following long-term health problems:

kidney disease
liver disease
diabetes, especially if it’s not well controlled
high blood pressure
heart failure
morbid obesity
If you’re ill or being treated in a hospital’s intensive care unit, you’re at an extremely high risk for acute kidney failure. Being the recipient of heart surgery, abdominal surgery, or a bone marrow transplant can also increase your risk.

How is acute kidney failure diagnosed

If you have acute kidney failure, you may have generalized swelling. The swelling is due to fluid retention.

Using a stethoscope, your doctor may hear crackling in the lungs. These sounds can signal fluid retention.

Results of laboratory tests may also show abnormal values, which are new and different from baseline levels. Some of these tests include:

blood urea nitrogen (BUN)
serum potassium
serum sodium
estimated glomerular filtration rate (eGFR)
urinalysis
creatinine clearance
serum creatinine
An ultrasound is the preferred method for diagnosing acute kidney failure. However, abdominal X-ray, abdominal CT scan, and abdominal MRI can help your doctor determine if there’s a blockage in your urinary tract.

Certain blood tests may also reveal underlying causes of acute kidney failure.

What is the treatment for acute kidney failure

Your treatment will depend on the cause of your acute kidney failure. The goal is to restore normal kidney function. Preventing fluids and wastes from building up in your body while your kidneys recover is important. In the majority of cases, a kidney specialist called a “nephrologist” makes an evaluation.

Diet
Your doctor will restrict your diet and the amount of liquids you eat and drink. This will reduce the buildup of toxins that the kidneys would normally eliminate. A diet high in carbohydrates and low in protein, salt, and potassium is usually recommended.

Medications
Your doctor may prescribe antibiotics to treat or prevent any infections that occur at the same time. Diuretics may help your kidneys eliminate fluid. Calcium and insulin can help you avoid dangerous increases in your blood potassium levels.

Dialysis
You may need dialysis, but it’s not always necessary, and it will likely only be temporary. Dialysis involves diverting blood out of your body into a machine that filters out waste. The clean blood then returns to your body. If your potassium levels are dangerously high, dialysis can save your life.

Dialysis is necessary if there are changes in your mental status or if you stop urinating. You may also need dialysis if you develop pericarditis or inflammation of the heart. Dialysis can help eliminate nitrogen waste products from your body.