What are kidneys and what do they do?
The kidneys are two bean-shaped organs found in the lower back. They are about the size of a fist. Kidneys are your bodies mechanism for cleaning your blood. They clean blood by filtering out excess water, sodium and waste products that enter your system through food. Healthy kidneys only filter out the “bad stuff” (waste) and keep “the good stuff” (protein), which helps the blood soak up water from other tissues. Damaged kidney filters may let protein slip through the filter and leak into the urine. As a result, not enough protein is left in the blood to soak up the water. The water then seeps from the blood into porous areas of your body’s tissues, causing swelling.