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What Is Dialysis?

Our kidneys work a lot like a garbage collection and disposal system. They remove extra fluids and waste products from the blood. This waste then leaves the body as urine (pee).

If the kidneys stop working properly, waste products can build up in the blood. This leads to medical problems that can quickly become life-threatening.

When the kidneys don't work right, doctors call it kidney failure. Dialysis (pronounced: dye-AL-uh-sis) is a medical treatment that can take over the job of filtering the blood until someone's failing kidneys heal or are replaced with a donated kidney through a kidney transplant.

Some people aren't good candidates for a kidney transplant. They may get dialysis treatments for the rest of their lives.

Dialysis (also sometimes called kidney dialysis) is a treatment for kidney disease — meaning it steps in to do the job of the kidneys and keep the body in balance. But it's not a cure. Dialysis alone won't heal a person's failing kidneys.

How Does Dialysis Work?

There are two kinds of dialysis: hemodialysis and peritoneal dialysis. If you need dialysis, you'll talk about the pros and cons of each option with your medical team and family. Together, you'll decide which kind is best for you. Sometimes people can switch from one kind of dialysis to the other if they want to.

  • Hemodialysis (pronounced HEE-muh-dye-al-uh-sis) is the most common way to treat advanced kidney failure. This kind of dialysis filters blood outside the body using a machine that's about the size of a dishwasher or a little smaller.

    The dialysis machine pulls blood from a person's body through a tube and filters it. After the blood has been cleaned, the dialysis machine pumps it back to the person's body through a second tube.

    Hemodialysis is usually done in a special clinic called a dialysis center.
  • Peritoneal (pronounced per-ih-tuh-NEE-ul) dialysis happens inside the person's body and is usually done at home. This kind of dialysis uses a special cleaning solution and the lining of the belly as a filter.

    The cleaning solution (called dialysate) is put into the abdomen through a catheter. Waste products and extra fluid are pulled from the lining of the belly into the cleaning solution. The solution is then drained out of the body through the catheter and thrown away.

Does It Hurt?

The needles used in hemodialysis can be uncomfortable for some people. Other than that, dialysis treatments are painless.

Can Anything Go Wrong?

Dialysis does carry some risks. For example:

  • Infection. Bacteria can get into the body where the catheter or needle go through the skin. That can cause an infection.
  • Low blood pressure. A drop in blood pressure during dialysis may cause breathing trouble, cramps, nausea, or vomiting.
  • Itching. Hemodialysis can cause itchy skin. This might be worse during or after a treatment.
  • Sleep problems. Dialysis treatments can lead to insomnia or sleep apnea, a condition in which someone briefly stops breathing during sleep.
  • Weight gain. The solution used in peritoneal dialysis contains sugar. If the body absorbs too much of the solution, it can be like eating lots of extra calories. This can cause weight gain and high blood sugar.

Taking Care of Yourself During Dialysis

If you're getting dialysis, you need to stay as healthy as possible to get the most out of your treatments and avoid the problems mentioned above.

Here are a few tips:

  • Eat the right foods. You'll need to get the right amount — not too much or too little — of fluids, salt, vitamins, and minerals each day. Too much potassium or phosphorus, for example, can affect your heartbeat or weaken your bones. Talk to the dietitian at your dialysis clinic about the right meal plan for you.
  • Take your medicines as prescribed. You will probably need medicines to control your blood pressure, help make red blood cells, and keep vitamin and mineral levels balanced. Follow your medical team's instructions about taking these — it's normal to forget or be confused by some medicine instructions, so ask your doctor if anything isn't clear. Talk to your doctor before taking any other medicines, vitamins, or supplements.
  • Plan ahead. If you'll be traveling, make sure you have everything you need to continue your treatments. If you need to go to a dialysis clinic in a different town, call ahead and make sure they can fit you into their schedule.

Except for special diets and the time needed for treatments, people getting dialysis usually live normal lives. Most of the time, they can go to school, take part in most sports and activities, go to prom, or just go out with friends as they usually would. Dialysis can be inconvenient, but it doesn't have to slow you down.

Date reviewed: May 2015