Hemodialysis

Healthy kidneys clean your blood and remove extra fluid in the form of urine. They also make substances that keep your body healthy. Dialysis replaces some of these functions when your kidneys no longer work. There are two different types of dialysis - hemodialysis and peritoneal dialysis. The following is about hemodialysis. For more information on peritoneal dialysis, click here.

When is dialysis needed?

You need dialysis if your kidneys no longer remove enough wastes and fluid from your blood to keep you healthy. This usually happens when you have only 10 to 15 percent of your kidney function left. You may have symptoms such as nausea, vomiting, swelling and fatigue. However, even if you don't have these symptoms yet, you can still have a high level of wastes in your blood that may be toxic to your body. Your doctor is the best person to tell you when you should start dialysis.

How does hemodialysis work?

In hemodialysis, a dialysis machine and a special filter called an artificial kidney, or a dialyzer, are used to clean your blood. To get your blood into the dialyzer, the doctor needs to make an access, or entrance, into your blood vessels. This is done with minor surgery, usually to your arm. For more information on hemodialysis access, click here.

How does the dialyzer clean my blood?

The dialyzer, or filter, has two parts, one for your blood and one for a washing fluid called dialysate. A thin membrane separates these two parts. Blood cells, protein and other important things remain in your blood because they are too big to pass through the membrane. Smaller waste products in the blood, such as urea, creatinine, potassium and extra fluid pass through the membrane and are washed away.

Where is hemodialysis done?

Hemodialysis can be done in a hospital, in a dialysis center that is not part of a hospital or at home. You and your doctor will decide which place is best, based on your medical condition, and your wishes.

How long will each hemodialysis treatment last?

In a dialysis center, hemodialysis is usually done 3 times per week for about 4 hours at a time. People who choose to do hemodialysis at home may do dialysis treatment more frequently, 4-7 times per week for shorter hours each time.

Your doctor will give you a prescription that tells you how much treatment you need. Studies have shown that getting the right amount of dialysis improves your overall health, keeps you out of the hospital and enables you to live longer. Your dialysis care team will monitor your treatment with monthly lab tests to ensure you are getting the right amount of dialysis. One of the measures your dialysis care team may use is called urea reduction ratio (URR). Another measure is called Kt/V (pronounced kay tee over vee). Ask your dialysis care team what measure they use and what your number is. To ensure that you are getting enough dialysis:

  • *your Kt/V should be at least 1.2 or
  • *your URR should be at least 65 percent.

Can I have hemodialysis at home?

Possibly. Many patients have their hemodialysis treatments at home. To learn more about home hemodialysis click here.

Do I need to eat a special diet?

Yes. Generally speaking, patients on dialysis are advised to increase their protein intake and limit the amount of potassium, phosphorus, sodium, and fluid in their diet. Patients with diabetes or other health conditions may have additional diet restrictions. It's important to talk with you dietitian about your individual diet needs.

Your dialysis care team will monitor your treatment with monthly lab tests to ensure you get the right amount of dialysis and that you are meeting your dietary goals. For more information on nutrition and hemodialysis, click here. For more information on understanding your lab values click here.

Can dialysis cure my kidney disease?

In some cases of sudden or acute kidney failure, dialysis may only be needed for a short time until the kidneys get better. However, when chronic kidney disease progresses to kidney failure over time, your kidneys do not get better and you will need dialysis for the rest of your life unless you are able to receive a kidney transplant.

Will I be uncomfortable on hemodialysis?

When you begin hemodialysis, the needles put in your fistula or graft may be uncomfortable. Most patients get used to this in time. Your dialysis care team will make sure you are as comfortable as possible during your treatment. Symptoms like cramps, headaches, nausea or dizziness are not common, but if you do have any of them, ask your dialysis care team if any of the following steps could help you:

  • *Slow down your fluid removal, which could increase your dialysis time.
  • *Increase the amount of sodium in your dialysate.
  • *Check your high blood pressure medications.
  • *Adjust your dry weight, or target weight.
  • *Cool the dialysate a little.
  • *Use a special medication to help prevent low blood pressure during dialysis.

You can help yourself by following your diet and fluid allowances. The need to remove too much fluid during dialysis is one of the things that may make you feel uncomfortable during your treatment.

How will I pay for my dialysis?

Dialysis is expensive. However, the federal government's Medicare program pays 80 percent of all dialysis costs for most patients. Private health insurance or state medical aid may also help with the costs. For more information on insurance click here.

I have heard I might have to reuse my dialyzer each treatment. Is this safe?

Before you reuse your dialyzer, your dialysis center cleans it according to careful guidelines. If done properly, reuse is generally safe. Before each treatment, your dialyzer must be tested to make sure it is still working well. If your dialyzer no longer works well, it should be discarded and you should be given a new one. Ask your dialysis care team if they have tested your dialyzer and if it still works well.

If you do not wish to reuse your dialyzer, your center may be willing to provide you with a new dialyzer for each treatment. Ask about the center's policy on reuse.

Can dialysis patients travel?

Yes. Dialysis centers are located in every part of the United States and in many foreign countries.

Before you travel, you must make an appointment for dialysis treatments at another center. The staff at your center may be able to help you arrange this appointment. For more information on traveling on dialysis click here.

Can dialysis patients continue to work?

Yes. Many dialysis patients continue to work or return to work after they have gotten used to dialysis. If your job has a lot of physical labor (heavy lifting, digging, etc.), you may need to change your duties. For more information on working with kidney disease click here.

For more on hemodialysis click on the following PDF brochures:
Hemodialysis: What you need to know
Getting Ready for a New Normal
A New Normal: Life on Dialysis—The First 90 Days

If you would like more information, please contact us.

© 2014 National Kidney Foundation. All rights reserved. This material does not constitute medical advice. It is intended for informational purposes only. Please consult a physician for specific treatment recommendations.