Location and Anatomy

The kidneys are twin organs shaped like kidney beans. They are located in the middle of your back below the ribs. In adults, each kidney is about the size of a closed fist and weighs about 3 pounds. A small number of people have only one kidney but lead completely normal lives.

Location of the Kidneys in the Body

Kidneys connect to the blood supply with an artery and a vein. They are also connected to the bladder by a tube called a ureter. The ureter carries the urine from the kidneys to the bladder and then out of the body.The kidneys are made up of a million tiny working units called nephrons. The number of nephrons is different for each person and that number is determined at birth. The body cannot make new nephrons if they are damaged.The kidneys contain approximately 8 miles of small blood vessels that form tiny filters; 200 quarts of blood are filtered and purified each day ( about 3 tablespoons a minute).

What Do the Kidneys Do?

Your body eliminates about two quarts of waste products, salt and excess fluid each day, in the form of urine. These waste products come from the breakdown of food you eat and the byproducts of normal muscle activity.

Normal Kidney Anatomy

In addition to removing wastes and fluid from your body your kidneys also:

  • Balance important minerals and chemicals in your body, such as sodium, potassium, phosphorus and calcium
  • Remove drugs and toxins introduced into your body
  • Produce hormones that help control your blood pressure, make red blood cells and help keep bones strong

As we get older, the tiny filters of the kidney suffer damage and scarring as part of normal aging. However, our body needs only about half of the normal kidney function to remain completely healthy.

Symptoms from low kidney function rarely occur until the function is less than 30%. Dialysis or kidney transplant is not needed until kidney function is less than 10 to 15%.