Dialysis

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Overview

What is dialysis

  • Dialysis is a procedure to remove waste products from your blood if your kidneys are not working properly.
  • You may need dialysis if you have a kidney condition, such as chronic kidney disease or acute kidney injury.
  • There are different types of dialysis. Some types you have in hospital and others you can have at home.
  • You'll usually need regular dialysis sessions, either every day or several times a week.

 Why do I need dialysis?

What dialysis is for

Your kidneys filter out waste products from your blood. The waste products pass out of your body in your pee (urine).

If your kidneys do not work properly, these waste products can build up in your body and make you very ill.

You may need dialysis if your kidneys are no longer able to filter your blood because they're damaged.

Damage to the kidneys can be caused by:

  • a sudden injury or illness (acute kidney injury) – you may need dialysis until your kidneys recover
  • chronic kidney disease – you will need dialysis for the rest of your life, or until you have a kidney transplant

Alternatives to dialysis

You may be unable to, or do not want to, have dialysis.

If this is the case, then there are treatments to help relieve symptoms and reduce some of the risks of kidney disease if you do not have dialysis.

For example, medicines can treat symptoms such as itchy skin, help control your blood pressure and prevent infections.

How is it performed?

How dialysis is done

Having dialysis

There are 2 types of dialysis:

  • haemodialysis – where your blood is filtered by a machine
  • peritoneal dialysis – where your blood is filtered by passing it through the natural lining inside your tummy (abdomen)

Your care team can discuss with you which type is the most suitable for you.

Haemodialysis

During haemodialysis, a dialysis machine is attached to a blood vessel using a thin tube. Your blood flows into the machine and is cleaned before flowing back into your body.

Around 10 weeks before starting treatment, you'll need a procedure to join an artery and a vein together to make a new blood vessel for the machine to attach to (usually in the inside of your arm, on your wrist or elbow). This is called an AVF (arteriovenous fistula).

The procedure is usually done under local anaesthetic and takes about an hour.

When the AVF is ready, you usually need to go to a local hospital or dialysis unit for haemodialysis. Each session takes around 4 hours. Most people need 3 sessions a week.

You may have the option of having dialysis equipment installed at home. Your care team can give you more information about home haemodialysis.

Peritoneal dialysis

During peritoneal dialysis, a special dialysis fluid flows from a bag into your tummy through a flexible tube called a catheter.

While it's inside you, the fluid absorbs waste products from your body. After a few hours, the fluid is drained into a separate collection bag.

About 2 weeks before treatment begins, you'll need a procedure to put the catheter into your tummy (abdomen). This takes about an hour and can be done under general anaesthetic (you're asleep during the operation), or local anaesthetic (medicines are used to numb your tummy).

When you're ready to start peritoneal dialysis, you can usually do it yourself at home. A nurse will show you how to do it.

You need to do peritoneal dialysis every day. Your care team will help you draw up a treatment schedule.

After a dialysis session

Both haemodialysis and peritoneal dialysis can leave you feeling tired and sick after a session.

Haemodialysis can also cause muscle cramps and dizziness during or shortly after a session.

Talk to your care team if you find these side effects are a problem as they may be able to help.

Advantages and Disadvantages

Possible complications of dialysis

Both types of dialysis have a risk of complications.

Complications of haemodialysis

Possible complications of haemodialysis include:

  • a skin infection around the new blood vessel that's used for the treatment (called an AVF or arteriovenous fistula)
  • bleeding from the new blood vessel
  • too much fluid in your body, leading to serious problems such as heart failure

Your care team will give you advice about problems to look out for and what to do if you have an infection or bleeding.

They can also let you know how much fluid you should drink each day, to help prevent too much fluid building up in your body.

Complications of peritoneal dialysis

Possible complications of peritoneal dialysis include:

  • a skin infection where the thin, flexible tube (catheter) enters your tummy
  • a hernia, where internal organs push through a weakness in the tummy muscles and create a lump
  • serious infections, such as peritonitis (infection of the tummy lining)

Your care team will give you advice about problems to look out for and what to do if you have an infection or bleeding.

Peritonitis needs to be treated straight away as it can lead to sepsis.

Ask for an urgent GP appointment or get help from NHS 111 if:

You're having dialysis and:

  • the skin around your AV fistula or abdominal catheter is painful, swollen or a different colour from usual
  • you have tummy pain or a lump in your tummy
  • you get a very high temperature, or start feeling hot, cold or shivery
  • your heart is beating more quickly than usual
  • you cannot pee or you're peeing much less than usual
  • the fluid that drains into your pouch (if you use one) looks cloudier than usual or has white flecks in it

You can call 111. Tell your GP or 111 if you’re having dialysis.

Call 999 if:

the blood vessel used for treatment (your AV fistula) starts bleeding – without treatment, the bleeding will not stop

Tell the call handler that you're bleeding from a haemodialysis fistula.

While waiting for medical help, follow any advice your care team has given you about what to do if your AV fistula is bleeding.

Side effects

Help and support with dialysis

Where to find help and support

If you're having dialysis, your care team will support you throughout the process. They will also be able to give you information about local support services.

There are also national charities that can offer support and information about kidney problems and treatments.

Kidney Care UK

Kidney Care UK has information about dialysis, financial support and benefits, and travelling.

Website: kidneycareuk.org
Kidney Care UK: haemodialysis
Kidney Care UK: peritoneal dialysis
Kidney Care UK: cost of living support and benefits
Kidney Care UK: travelling with chronic kidney disease



The information on this page has been adapted by NHS Wales from original content supplied by NHS UK NHS website nhs.uk
Last Updated: 04/11/2026 13:25:37