The term 'kidney-based' can be summarized by the word 'renal, ' which is a five-letter word. The kidneys are two bean-shaped organs located in the abdomen that filter waste products from the blood and excrete them in the form of urine. They also help to regulate the body's fluid balance, electrolyte levels, and acid-base balance. Kidney-based diseases, such as renal failure, can occur when the kidneys are not functioning properly.