Mariah Carey sent a shocking tweet this morning, announcing that her husband, Nick Cannon, had been hospitalized with mild kidney failure.

“Please pray for Nick as he’s fighting to recover from a mild kidney failure. #mybraveman,” the singer wrote.

What is mild kidney failure, and did the fact that Cannon is African-American put him at a greater risk? According to the National Kidney Foundation, for every 1 million African-Americans, 998 will be affected by kidney disease, as compared to 273 whites.

Dr. Bryan Becker, immediate past president of the National Kidney Foundation, says Cannon’s hospitalization may be due to acute kidney injury (the term “mild kidney failure” does not exist), which is when a person’s kidney function has decreased.

“I don’t know that he has kidney failure on dialysis,” Dr. Becker tells “I think it may be that just his kidney numbers, his serum creatinine measure, decreased. It could be something as simple as being in Colorado — where Cannon and Carey are currently vacationing — not drinking enough fluids, and being dehydrated.”

“Though the African-American population is at greater risk for chronic disease, for acute kidney injury like this, there does not seem to be any increased risks [for African-Americans],” he adds.

So what could have caused Cannon’s acute kidney injury? “Viral illness, stomach problems, infections in his lungs,” says Becker.