Don't you love swimming in a cool, blue pool? Splashing around in that clear water, floating like a lily pad, swimming like a shark. But imagine if the water wasn't clear or clean. What if it was filled with leaves, dirt, hair, and drowned bugs? Yeeech! You'd be one unhappy shark.

You'd probably want to clean it out before diving in. And you'd want to make sure the pool has a filter that removes the dirt, leaves, and other uninvited guests.

The Kidneys and What They Do

That's kind of what your kidneys do for you. Your kidneys are fist-sized organs, shaped like beans. They're below your ribs, toward the back.

When waste that's left over from breaking down food and your body's other activities naturally builds up in your blood, your kidneys act like a filter to clean waste from your blood. Then they mix the waste with a little water. That's what urine is — body waste mixed in water. The urine goes to your bladder, which you empty when you pee. Goodbye, waste!

When Kidneys Don't Work Right

In addition to removing wastes from your bloodstream, the kidneys also make and regulate hormones and other chemicals in your body. When the kidneys aren't working correctly, your body can develop several problems, including:

• joint problems
• body aches and pains
• fatigue
• bone problems
• itchy skin
• sleep problems
• anemia (say: uh-nee-mee-uh), a problem in which the number of red blood cells or hemoglobin in the blood is too low

What Is Dialysis?

When someone's kidneys can no longer do their job and can't get better, a person has chronic kidney disease. A doctor might say the kidneys are failing. This means they are not working well and the person may need help. The person may be losing weight or feeling tired and sick.

A medical treatment called dialysis (say: dye-al-ih-sis) can take over the job of filtering your blood. Through dialysis, a person is hooked up to an artificial filtering system that removes waste from the blood. Not that many people younger than 19 receive dialysis — about 2,300 young people in the United States do.

How Does Dialysis Work?

There are two dialysis methods: hemodialysis and peritoneal dialysis. Hemodialysis (say: hee-mo-dye-al-ih-sis) uses a filtering machine to remove waste and extra fluid from your blood. In the second type, called peritoneal (say: per-uh-tuh-nee-ul) dialysis, the actual filtering is done by the lining of the person's belly! Kids who need dialysis are most likely to get this type.

With hemodialysis, the person's blood travels through tubes to the machine — called a dialyzer (say: dye-uh-lye-zer) — which removes extra fluids and waste. Once the blood is cleaned, the machine sends it back to the person through another tube. This process typically takes about 4 hours and has to be done three times each week in a dialysis clinic. Some clinics will train people so that they can perform their treatments at home.

The most commonly used type of peritoneal dialysis for kids, called continuous cyclic dialysis, uses a machine to put a cleansing solution called dialysate (say: dye-al-ih-sate) in the person's belly, usually eight to 12 times each night. As blood flows naturally through the blood vessels in the belly, extra fluid and waste products in the blood seep out into the dialysate in the belly. Meanwhile, the dialysate cleanses the blood and rebalances the blood's chemistry. After about an hour, the machine drains the dialysate from the belly.

Some kids can sleep through dialysis. Others might find it uncomfortable and inconvenient, so a different type of peritoneal dialysis might be used. The good news is that afterward, body fluid levels are balanced and waste is gone.

Other Options

In some cases, a kid can get a new kidney. This is called a transplant, which means receiving an organ from another person's body. This operation can be a big help to kids with kidney disease because after the surgery they may no longer need dialysis treatments.

But kids who need dialysis can benefit from improving technology. Improvements to dialysis machines mean that the machines are smaller and that receiving dialysis is getting easier. This makes it easier for kids with kidney failure to do everyday things and enjoy activities, just like other kids.

One doctor puts it this way to kids who need dialysis: Dialysis is part of your life, but it isn't your life or who you are.

Reviewed by: Steven Dowshen, MD
Date reviewed: January 2012
Originally reviewed by: Laszlo Hopp, MD