The kidneys are an essential part of the urinary system. The bean-shaped organs regulate electrolytes, maintain acid-base balance and regulate blood pressure. They also serve as a natural filter for the blood and remove waste from the bladder. Each human has two kidneys but can function effectively with one. Every day, a person's kidneys process about 200 quarts of blood and sift out about 2 quarts of waste and extra water, which become urine.
The kidneys are located in the abdominal cavity, near the middle of the back, just below the rib cage. There is one kidney located on either side of the spine. To find your kidneys, put your hands on your hips, then slide your hands up until you can feel your ribs. If you put your thumbs on your back, your kidneys are directly between that area and the area below your ribs.
Right Versus Left
The right kidney sits just below the diaphragm behind the liver, while the left is below the diaphragm, behind the spleen. Because the abdominal cavity is not symmetrical, the right kidney is usually slightly lower than the left.
The upper parts of the kidneys are partially protected by the 11th and 12 ribs. Each kidney is also surrounded by two layers of fat.
Both kidneys are about 4 inches long and about 2 1/2 inches wide. This size allows them to be small enough sit comfortably within the abdominal cavity, but large enough to effectively filter waste from your body.
Why This Location Is Important
Your kidneys receive blood from the renal artery, process it, then return the processed blood to the body and remove the wastes in the urine, sending this urine to the bladder. Each kidney contains up to a million units called nephrons, a collection of tiny filtering blood vessels.