Acute Kidney Injury

This information is useful for children, adults, and older adults
woman in kidney pain, possibly from acute kidney injury

Credit: Getty Images

Your kidneys do the important work of cleaning your blood as it moves through your system. Hundreds of thousands of tiny units in your kidneys (called nephrons) filter waste and toxins out of the blood to produce urine, which then flows into the bladder.

Sometimes, though, there is a potentially serious problem. Acute kidney injury (AKI) is an episode of sudden kidney damage or failure. It causes waste products, like creatinine and urea, to build up in your blood and can cause significant damage to the rest of your body. There are multiple levels of kidney injury, varying from mild to severe. In severe cases, your brain, heart, and lungs can be affected, and you can die.

Multiple conditions can cause AKI. Researchers have shown that infection, conditions that cause lack of blood flow to the kidneys, or conditions and medications that damage the kidneys themselves can all cause a sudden kidney function decline. To be sure, AKI is most common in hospital settings, especially in critical care patients.

Acute kidney injury can be difficult to detect unless the doctor is trained to look for it, says Yale Medicine nephrologist F. Perry Wilson, MD. This is because there are rarely any symptoms until kidney function is severely damaged.

If left untreated, AKI has a very high mortality rate. If the underlying cause is diagnosed and treated, your prognosis will depend on how much damage has been done to the kidneys.