Patient Guide

The Healthy Kidney

The healthy balance of our body’s chemistry is due in large part to the work of two organs: your kidneys. These bean-shaped organs are located just above the waist at the back, and are partially protected by the ribs. Each kidney is about the size of your fist.

Healthy kidneys work very hard – 24 hours per day, like a sieve, continuously cleansing the blood through tiny filters called nephrons. Each kidney has around one million nephrons. The kidney retains all of the nutrients and good things that you need in the bloodstream. Any remaining excess water, waste products from your diet and metabolism, or harmful substances such as drugs or toxins, are then passed to the bladder and removed from the body in your urine.

Every day your kidneys filter over 200 liters of fluid: most of this is reabsorbed, with about 1.5 to 2 liters removed as urine. While this is a vital function, the kidneys are also responsible for some other vital functions such as controlling blood pressure and preventing anemia.

The importance of your kidneys:
• Removing excess water from your body
• Removing waste products and toxins from your diet and metabolism
• Maintaining balance of important salts such as sodium and potassium (electrolytes)
• Regulating acid balance in the body, keeping it neutral
• Producing erythropoietin (EPO), an important hormone that enables the bone marrow to make red blood cells and prevent anemia
• Helping the body to control blood pressure
• Activating vitamin D, which is essential to absorb calcium
• Maintaining calcium and phosphate at a normal range, to keep your bones healthy


Kidney failure

There are times when the kidneys are no longer able to maintain vital functions because of disease or physical damage. When the kidneys are not capable of removing excess water and waste from the blood, they cause discomfort or other specific symptoms, which include:

• Fatigue
• Nausea and vomiting
• Breathing difficulty
• Difficulty falling asleep
• Swelling of the face, hands, and feet
• Loss of appetite
• Itching
• High blood pressure (hypertension)

Some symptoms and signs occur when urea and other waste products build up in the body, because the kidneys were unable to eliminate them. The increase in these substances is called uremia. These symptoms may be diagnosed as kidney failure or disease.