Your Kidneys Filter About 150 Quarts of Blood a Day

Each kidney is only about the size of a fist, but the pair never stop working. The National Institute of Diabetes and Digestive and Kidney Diseases, part of the U.S. National Institutes of Health, states that healthy kidneys filter about a half cup of blood every minute, removing wastes and extra water to make urine. Over a single day that adds up to about 150 quarts of blood. Very little of it leaves the body. Most of the water and other substances that are filtered are returned to the blood, and only 1 to 2 quarts become urine. The work is done by tiny units. Each kidney is made up of about a million filtering units called nephrons, and each nephron has a filter, called the glomerulus, and a tubule.