Philadelphia is hosting a free screening Friday for those who want to know more about their risk for kidney disease.

The leading causes of kidney disease are diabetes and high blood pressure, and the rates of those health problems are disproportionately high in Philadelphia.

Kidney disease is often called a silent killer, said Tenee Hawkins, a spokeswoman for the American Kidney Fund. The nonprofit receives support from dialysis centers and pharmaceutical companies.

"Nine out of 10 American with early kidney disease don't even know they have it," Hawkins said.

Not everyone who takes part in the screening will need the full suite of tests, she said, adding that the  approach is kind of like triage.

"We're getting background information and paper on the risk assessments, and we're taking their blood pressure and blood glucose first before expending the extra resources toward an eGFR, or kidney-function test," she said.

The kidney health event will take place from 10 a.m. to 3 p.m. Friday at the Municipal Services Building Plaza at 1401 JFK Boulevard. directly across from City Hall.