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Dialysis (Vascular) Access

Hemodialysis access, or vascular access, is a way to reach the blood for hemodialysis.  The access allows blood to travel through soft tubes to the dialysis machine where it is cleaned as it passes through a special filter, called a dialyzer. An access is placed by a minor surgery.


Dialysis is a treatment that can take over the job of the kidneys. It is done during regular visits to a clinic. Blood passes from the body to a machine. The machine will clean the blood and return it to the body.

There are two types of dialysis. This fact sheet will focus on hemodialysis.

Reasons for Procedure

The kidneys have many important jobs. They clear toxins out of the blood and help balance salt levels. Dialysis may be needed if the kidneys are not able to work well. It may be started when the kidneys have lost more than 90% of their function. Hemodialysis can help to:

  • Remove waste and excess fluid from the blood
  • Control blood pressure
  • Keep a safe level of salts in the body, such as potassium, sodium, and chloride

Dialysis may be used short term to allow the kidneys to rest and heal. It may also be done to treat a poisoning or drug overdose. Dialysis can quickly remove toxins from the bloodstream.

Dialysis may be permanently needed for severe kidney damage. It can improve quality and length of life in people with severe kidney disease.

Possible Complications

Problems are rare, but all procedures have some risk. The doctor will go over some problems that could happen, such as:

  • A drop in blood pressure during hemodialysis
  • Problems with heart rhythm
  • Infection
  • Disruption of calcium and phosphorus balance, resulting in weakened bones

Heart problems may increase the risk of problems from hemodialysis.

What to Expect

Prior to Procedure

A fistula may be needed to allow better access to blood flow for long term dialysis. A surgery is needed to make the fistula. It will take 4 to 6 months before it can be used. Your care team will connect directly to blood vessels until it is ready.

The hemodialysis team will meet with you to talk about:

  • Any allergies you have
  • Current medicines, vitamins, herbs, and supplements that you take and if you need to stop taking them before hemodialysis
  • Tests that will need to be done before surgery, such as giving medicine to prevent blood clotting and taking weight, blood pressure, and temperature measurements


A medicine may be placed over the area the needle is placed. This will help to numb the skin.

Description of the Procedure

Hemodialysis is done at a dialysis center or hospital. It may be done at home with assistance. You will be asked to sit. Blood flow will be accessed through a large IV in one of the major veins of the neck. The fistula will be used if one is available.

Blood will pass through one needle into a tube to a machine. The machine will filter and clean the blood. It will then be passed out through a tube and back into the body.

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How Long Will It Take?

Hemodialysis is usually done three times a week. Each treatment can last 3 to 4 hours.

Will It Hurt?

You will not feel the blood exchange. There may be some discomfort when the needle is placed.

Post-procedure Care

Your blood pressure will be checked. A decrease can cause nausea, headache, or cramps. This may happen less often in later treatment. Once blood pressure is stable, you will be able to leave.

Most people go back to normal activities after treatment. A special diet may need to be followed to decrease stress on the kidneys.

Problems to Look Out For

Call the doctor if you have:

  • Signs of infection, such as fever and chills
  • Redness, swelling, or increased pain at the catheter or tube insertion site
  • Increased bleeding or other leakage from site
  • Nausea or vomiting
  • Abdominal pain
  • Lightheadedness or weakness

If you think you have an emergency, call for medical help right away.


  • Hemodialysis. National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: https://www.niddk.nih.gov/health-information/kidney-disease/kidney-failure/hemodialysis.
  • Hemodialysis. National Kidney Foundation website. Available at: https://www.kidney.org/atoz/content/hemodialysis.
  • Peritoneal dialysis for end-stage renal disease. EBSCO DynaMed website. Available at: https://www.dynamed.com/management/peritoneal-dialysis-for-end-stage-renal-disease.