The kidneys are a pair of vital organs that perform many functions to keep the blood clean and chemically balanced. Understanding how the kidneys work can help a person keep them healthy. Every day, a person’s kidneys process about 200 quarts of blood to sift out about 2 quarts of waste products and extra water. The wastes and extra water become urine, which flows to the bladder through tubes called ureters. The bladder stores urine until releasing it through urination. It is important to drink plenty of water to keep the kidneys well hydrated.