The kidneys are two bean-shaped organs located under the rib cage on either side of the spine in the lower back. Each kidney is about the size of an adult fist and weighs about a half pound.
Each kidney has approximately one million nephrons that perform the work of the kidney. When you have kidney disease, nephrons become damaged and cannot work properly. In the beginning stages of kidney disease, the healthy nephrons can do the extra work of the damaged nephrons.
As kidney disease continues, more nephrons become damaged and eventually the nephrons that are left cannot function well enough to keep you healthy. Waste products will then build up in the body and you start to feel sick.
Although it may appear that kidney disease occurs suddenly, most of the time it has been happening slowly, often for many years.