The kidneys remove waste from the blood by filtering about 120 to 150 quarts of blood per day to produce 1 to 2 quarts of urine daily. After the blood is filtered, it returns into the body through the renal veins.
The kidneys are two bean-shaped organs located below the rib cage. They are about the size of a fist. Each kidney consists of about 1 million units called nephrons. Each nephron contains a glomerulus, which is a small filter attached to a tube. The blood passes through the nephrons, which filter out the fluid and waste products. The waste products are concentrated in urine and much of the fluid returns to blood.
Besides filtering the blood, the kidneys also produce and regulate a number of hormones in the body to help red blood cell production and control blood pressure. They also maintain body fluid at the right levels so that the body can function correctly. Another function of the kidneys to regulate the amount of salt, water and other chemicals that move around the body. Well-functioning kidneys are essential for the overall state of health, so any sign of kidney failure should be treated very carefully, advises WebMD. Individuals who are at risk of chronic kidney disease should talk to their doctor about regular checks.