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by Carmack A



Dialysis is a treatment that takes over the job of your kidneys when they fail. The kidneys perform many functions that help your body stay healthy. They help clear toxins out of your blood and help your body balance salt levels. Most people begin dialysis when their kidneys have lost 85%-90% of their ability. You may be on dialysis for a short time, or you may need it for the rest of your life.
If you have kidneys that are not working and the damage is not reversible, you have end stage renal disease (ESRD). ESRD is caused by conditions such as diabetes, kidney cancer, drug use, high blood pressure, or other problems. Dialysis is not a cure for ESRD, but it does help you feel better and live longer.
There are 2 types of dialysis: hemodialysis and peritoneal dialysis. This fact sheet will focus on hemodialysis.

Reasons for Procedure

The main functions of hemodialysis are to:
  • Remove waste and excess fluid from your blood
  • Control blood pressure
  • Keep a safe level of salts in the body, such as potassium, sodium, and chloride
It may also be done to remove toxins from the bloodstream quickly. It can be used in cases of poisoning or drug overdose.

Possible Complications

Problems from the procedure are rare, but all procedures have some risk. Your doctor will review potential problems, like:
  • A drop in blood pressure during hemodialysis
  • Heart rhythm abnormalities
  • Muscle cramps
  • Nausea, vomiting
  • Headaches
  • Infection
  • Feeling hot, sweaty, weak, and/or lightheaded
  • Inflammation of the heart sac—pericarditis
  • Neurological problems
  • Disruption of calcium and phosphorus balance, resulting in weakened bones
If you have heart problems, this may increase your risk of complications from hemodialysis.

What to Expect

Prior to Procedure

Usually, before your first hemodialysis, you will have some sort of tubing attached to a large vein. The tubing will make blood flow from your body to the machine and back more easily. If you will be on hemodialysis for a long time, you may have had surgery to create a shunt or a fistula, which makes access to a large vein easier. Fistulas may need as long as 2–3 months to fully heal before they can be used.
Before your hemodialysis, you will:
  • Have your weight, blood pressure, and temperature taken
  • Be given heparin to prevent blood clotting.


If needle insertion is needed, you will be given a topical pain-numbing medication.

Description of the Procedure

Hemodialysis is done at a dialysis center or hospital. It may be done at home with assistance.
During the procedure, blood is filtered through an artificial kidney machine, called a dialyzer. The blood travels from your body to the machine through tubes inserted into a large vein in your body. After the blood is filtered in the machine, it travels back into your body through another tube.
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How Long Will It Take?

Hemodialysis is usually done 3 times a week. Each treatment can last 2-4 hours. The specific time needed depends on:
  • How much kidney function remains
  • How much fluid weight gain has occurred since the last treatment
  • The amount of waste in the body
  • Body size
  • The level of salts in your body, such as sodium, potassium, and chloride

Will It Hurt?

In general, hemodialysis does not cause pain. You will not feel the blood exchange. There may be some temporary discomfort inserting the needle or tube.

Post-procedure Care

At the Care Center
Your blood pressure will be monitored. After the procedure is complete and blood pressure is stable, you can continue daily activities.
At Home
Certain dietary guidelines should be followed. This will help maintain overall health and optimize treatment effects. Talk to your doctor about your specific dietary needs.
Follow your doctor's instructions.
Your doctor may give you various medications. These include, but are not limited to:
  • Blood pressure medications
  • Calcium supplements or multivitamins
  • Phosphorus binders—to lower phosphorus levels in the blood
  • Diuretics—to remove excess fluid
  • Stool softeners or laxatives—to prevent or treat constipation, which can be caused by decreased fluid intake
  • Iron supplements—to increase iron intake, which is important to make red blood cells
  • Medications to stimulate the body to produce more red blood cells

Call Your Doctor

It is important to monitor your recovery. Alert your doctor to any problems. If any of the following occur, call your doctor:
  • Signs of infection, including fever and chills
  • Redness, swelling, warmth, increasing pain, excessive bleeding, or discharge at the catheter or tube insertion site
  • Nausea or vomiting
  • Abdominal pain
  • Lightheadedness or weakness
If you think you have an emergency, call for medical help right away.


The Kidney Dialysis Foundation
National Kidney and Urologic Diseases Information Clearinghouse


Health Canada
The Kidney Foundation of Canada


Hemodialysis. National Kidney Foundation website. Available at: Accessed March 7, 2016.
Dialysis for end-stage renal disease. EBSCO DynaMed Plus website. Available at: Updated September 23 2016. Accessed October 10, 2016.
Treatment methods for kidney failure: Hemodialysis. National Kidney and Urologic Diseases Information Clearinghouse website. Available at: Updated June 2014. Accessed March 7, 2016.

Revision Information

  • Reviewer: EBSCO Medical Review Board Adrienne Carmack, MD
  • Review Date: 03/2017
  • Update Date: 04/29/2014
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