When the kidneys are healthy, one of their main jobs is to clean the blood. Two normal kidneys can filter wastes and excess fluid from hundreds of pints of blood each day. In this way, they maintain the chemical balance the body needs to stay healthy and alive.
If both kidneys fail (end stage renal disease), wastes produced by normal cell functions build up in the blood (uremia). Over time, this can threaten your health.
The kidneys are part of a system that removes wastes from your body. For this system to work, the kidneys and urinary tract must do their jobs fully.
Vessels Carry Blood
Tiny blood vessels inside the kidneys carry blood to the filtering units. These vessels also shrink or expand to control the pressure inside the kidneys.
Filters Clean Blood
Blood is cleaned as it passes through the filtering units. Wastes and excess fluid are taken out to make urine. The proper amounts of clean fluid and vital chemicals (salts and enzymes) are returned to the blood.
Urinary Tract Removes Wastes
Two tubes, called the ureters, connect the kidneys with the bladder (where urine collects). When the bladder is full, the urine is passed out of the body through a tube (urethra).