How Your Kidneys Work

Your two kidneys serve a number of functions that are vitally important to your health. As blood moves through these organs, the kidneys filter out water, salts and waste products, and pass them out of the body as urine. By doing this, the kidneys help balance the fluids and chemicals in your body.

In addition to acting as filters, the kidneys also release hormones that are important in controlling blood pressure, forming red blood cells and making vitamins to keep your bones healthy.

Defining Renal Function
When doctors talk about kidneys, they often refer to renal function. "Renal" is another term used in reference to the kidneys. Most people are born with two kidneys. Some people are born with only one kidney. With one kidney you may live a completely normal life.

When it comes to the important work the kidneys perform, 100 percent renal function is really more than is needed to do the job. In fact, it is possible to feel healthy with less than 20 percent of normal renal function.

Kidney Disease
Kidneys can fail for a number of reasons. The two most common causes of kidney failure are diabetes and high blood pressure. Kidney problems can also result from a hereditary disease known as Polycystic Kidney Disease (PKD), from prolonged use of some over the counter medicines, or from a direct trauma to the kidneys as could occur in an accident or sports injury.

Some kidney problems can be reversed with medical treatment. However, if your renal (kidney) function falls below 15 percent, your kidneys will no longer be able to support your body's health. Waste materials will stay in your body. Your body's chemical balance will become upset - and you will become ill.

If you reach a point where your kidneys can no longer function, your condition is called End Stage Renal Disease or ESRD. To stay alive, you will need to undergo dialysis or have a kidney transplant.

Treatment Options
If your kidney failure has reached the point of End Stage Renal Disease (ESRD), you have two options for treatment: Dialysis and Kidney Transplantation.

• Dialysis:Kidney dialysis is a method for removing waste products from your blood stream through the use of a machine or other form of "outside" assistance. There are two forms of dialysis: hemodialysis and peritoneal dialysis.

With hemodialysis you are connected through two intravenous needles to a machine that allows your blood to flow through a filtering system that removes waste products. The cleaned blood then flows back into your body. Patients using this kind of dialysis must go to a treatment center three times a week to receive the dialysis treatment. Each treatment can take up to 4 hours.

Peritoneal dialysis is a treatment method in which a special fluid called dialysate is allowed to flow into the abdominal cavity. Once there, waste products enter into the dialysis fluid. After a few hours, the fluid is drained away. This method involves the use of fluid bags, which must be changed several times a day. However, patients can learn to do the procedure at home, so that trips to a doctor's office or treatment center for routine checkups need only occur on a monthly basis.

• Kidney Transplantation: Kidney transplantation is an option chosen by many patients who want an alternative to the restrictions of dialysis. In a kidney transplant, a kidney is placed into the pelvis on either the right or left side. Your own kidneys are left in place in most cases. The healthy kidney can come from a living donor or from an anonymous organ donor who has recently died. Almost 100,000 people have been treated through kidney transplantation since 1954, when this surgery was first performed.