Acute kidney injury is a sudden loss of kidney function that can develop within a few hours or over a few days. As many as 10 percent of hospitalized patients and up to 22 percent of intensive care unit (ICU) patients worldwide experience acute kidney injury, according to the study authors.

For the study, the researchers reviewed information from more than 1.3 million hospital patients. Nearly 19,000 had acute kidney injury, the investigators found.

The study showed that having diabetes or being older, male or black was tied to an increased risk of acute kidney injury. But the strongest risk factor was abnormal results on blood and urine tests of kidney function. And this was true even if the tests were only mildly abnormal, the study found.

Preventing an acute kidney injury from developing is crucial, the experts said.

"Once a patient suffers an acute kidney injury, we have no effective treatment, so it is important to focus on prevention whenever possible," study co-author Dr. Morgan Grams, an assistant professor of epidemiology at Johns Hopkins Bloomberg School of Public Health in Baltimore, said in a school news release.

"Our research tells us that regardless of why someone is in a doctor's care, that doctor needs to pay very close attention to these basic markers of kidney function," she added.

The findings were published in the May online edition of the American Journal of Kidney Diseases.

Acute kidney injury, which can lead to irreversible kidney damage, is often caused by certain medications, medical tests that require iodine contrast, or by dehydration. The condition can lead to longer hospital stays, chronic kidney disease, kidney failure and death.

"Reducing acute kidney injury worldwide can be accomplished simply by paying close attention to the kidney levels of patients in hospitals and ICUs," said Grams, who is also an assistant professor of nephrology at the Johns Hopkins University School of Medicine. "It may really be that simple."