A person has two kidneys, each one being approximately the size of your clenched fists. They are located on either side of the spine on the lower ribs. The kidneys as an organ clean your blood of waste and water produced by the breakdown of food, medication and other bodily processes. To put things into perspective, the kidneys process and clean all the blood in a person’s body. The actual removal of waste is done by millions of tiny structures called nephrons in the kidneys. This process is called filtration. There are approximately 2 to 3 million nephrons in one kidney. While the nephrons reabsorb most of the water and other important elements from the blood, the waste and remaining water are removed as urine.