Overview
Contrary to what the name might suggest, acute kidney injury is not a result of a physical blow or injury to the kidneys. Acute kidney injury (AKI), also known as acute renal failure, occurs when the kidneys suddenly stop working, normally as a complication of another illness. Typically seen in older adults who may be experiencing other conditions, it is essential that the cause of acute kidney injury is detected as early as possible for the best chance at treatment.
Without prompt treatment, unhealthy levels of waste can build up in the blood, making it difficult for your kidneys to remove that waste, as well as affecting other organs within the body. If treated early, many people are able to return to normal kidney function, especially those whose kidneys were functioning properly prior to AKI occurring.
In some cases, AKI can lead to chronic kidney disease, which could cause the kidneys to stop working entirely.
Causes of Acute Kidney Injury
Acute kidney injury can have a variety of causes, however most commonly by reduced blood flow to the kidneys. This reduced blood flow may be a result of low blood volume from an excessive bleeding event, or dehydration stemming from excessive vomiting or diarrhea. AKI could also be caused from certain medications that are taken to reduce blood pressure, such as ACE inhibitors or NSAIDs.
Direct damage to the kidneys is also a cause of acute kidney injury, which could occur from events such as allergic reactions to medication, infections, conditions such as cancer, or even drug and alcohol abuse. Finally, blockage to the urinary tract could lead to AKI, which may be caused by an enlarged prostate, kidney stones, blood clots, or certain types of cancer.
People who are at increased risk of AKI include those who:
- Were hospitalized with COVID-19
- Are age 65 or older
- Have a history of kidney disease
- Have severe high blood pressure
- Have heart disease
- Are suffering from severe dehydration
- Take insulin for diabetes

Symptoms of Acute Kidney Injury
It is not always possible to immediately identify the cause of acute kidney injury. Some milder forms of acute kidney injury may not present any signs or symptoms and are only detected through medical tests and screening. Catching severe forms of AKI is critical to treating it prior to it leading to more severe kidney disease or failure. Even if mild, it is important to take AKI very seriously and begin treatment right away.
Common symptoms of AKI may include:
- Less frequent urination
- Swelling in legs, ankles, or feet
- Feeling confused
- Pain or pressure in the chest
- Inability to catch your breath
- Feeling drowsy or weak
- Feeling sick to your stomach
To screen for AKI, even if little to no symptoms are presented, your doctor may order blood and urine tests to check for signs of kidney failure, and order imaging tests such as an ultrasound to look at your kidneys for abnormalities.

Treatment
Identifying the underlying cause of acute kidney injury is essential to determining the type of treatment needed. Remedies for AKI, especially if caught early or in a mild form, may be as simple as increasing fluid intake and the prescription of antibiotics. In more severe cases, hospitalization may be necessary in order to better control the AKI and prevent it from worsening.
If the kidneys have been severely damaged, dialysis may be needed to assist the kidneys in their recovery. Post-recovery, an eating plan may be prescribed to further help your kidneys heal.
Treatment of AKI may not prevent the likelihood of reoccurrence in the future. Regular visits with your doctor and screenings to test your kidney function is vital to lowering your chances of AKI and protecting your kidneys from injury or damage.