>> WHAT THEY ARE: A pair of bean-shaped organs about the size of your fist, at the bottom of your rib cage, close to your back. >> WHAT THEY DO: Clean your blood by removing waste and managing minerals and fluids. >> WHY YOU NEED TO KNOW ABOUT THEM: If they stop working, waste builds up. Kidney diseases are the fifth leading cause of death for black women and the ninth for black men. >> HOW YOU CAN KEEP THEM HEALTHY: Kidney diseases are caused by the same factors that contribute to diabetes and high blood pressure: poor diet and lack of exercise. So lighten up on the salt, sugar and fat, and work it.