Reports of professional athletes who abuse anabolic steroids are increasingly common. Most people know that using steroids is not good for your health, but until now, their effects on the kidneys have not been known. Leal Herlitz, MD (Columbia University Medical Center) and her colleagues recently conducted the first study describing injury to the kidneys following long-term abuse of anabolic steroids. The investigators studied a group of 10 bodybuilders who used steroids for many years and developed protein leakage into the urine and severe reductions in kidney function. Kidney tests revealed that nine of the ten bodybuilders developed a condition called focal segmental glomerulosclerosis, a type of scarring within the kidneys. This disease typically occurs when the kidneys are overworked. The kidney damage in the bodybuilders has similarities to that seen in morbidly obese patients, but appears to be even more severe.