Unseen and unsung, your kidneys are toiling away, in the small of your back behind your ribs. These twin wonders dump waste from decomposing nutrients and meds, pump out excess water and salts, and make hormones that do everything from preventing anemia to regulating blood pressure.

Many HIVers didn’t pay their kidneys much mind until indinavir (Crixivan) came along—it can form crystals in the urine. In one study, about 4 percent of people taking Crix had kidney stones (marked by back pain and blood in the urine); 8 percent had smaller crystals and milder symptoms; and 20 percent had crystals without symptoms. Low water intake increases your odds of getting crystals—and boosting Crix with ritonavir (Norvir) increases the odds for stones.

A freakier kidney setback is HIV-linked nephropathy, a chronic condition that erodes the kidneys’ ability to filtrate and hikes levels of protein in the urine. Nephropathy is the leading cause of renal (kidney) failure in HIVers—and more than 90 percent who develop it are black.
Absence of early symptoms makes screening crucial: Have your doc check your pee for protein and your blood for increased creatinine (a product of muscle tissue). The optimal treatment hasn’t been nailed, but suppressing viral load with HIV meds seems to help, as do blood-pressure drugs called ACE inhibitors. Fear of kidney calamities should drive an HIVer to drink—water, that is, and plenty of it.