The kidneys act as filters for the body, removing waste from the blood and getting rid of it via the urine. If your kidneys are not working properly, waste can build up in your blood. Dialysis can help damaged kidneys by performing the task of filtering.
What is dialysis?
Dialysis is a way to artificially clean the blood if your kidneys are no longer able to cope.
There are two main types of dialysis:
- haemodialysis, in which your blood is circulated through a dialysis machine for cleaning
- peritoneal dialysis, which uses the peritoneal membrane in your abdomen (tummy) to filter blood allowing cleaning to take place inside the body
When is dialysis needed?
Dialysis is most often required due to kidney failure.
Kidney failure can sometimes happen over a short period (days or weeks) – this is called acute kidney failure – as the result of a serious illness or accident.
More commonly, kidney failure is the result of chronic kidney disease, where kidney function worsens over many years. Dialysis is usually started when the person affected is finding it hard to keep up with their usual life. At this stage, the kidneys are usually working only about 10% of how they should be working.
Dialysis must be done for the rest of your life, unless you have a kidney transplant.
How does dialysis work?
During haemodialysis your blood is cycled through a special machine called a ‘dialyser’, which removes waste from your blood before pumping it back into your body. The blood leaves and then returns to your body through a needle, usually in your arm or leg.
During peritoneal dialysis fluid is pumped into a space in your abdomen called the peritoneal cavity. The fluid enters and leaves through a catheter, which is a thin soft tube about 30 cm long that stays in place permanently. Waste from the blood is drawn into the fluid through a membrane in your abdomen and then removed from your body.
Peritoneal dialysis can be performed manually (continuous ambulatory peritoneal dialysis) or controlled by a machine (automated peritoneal dialysis).
Life on dialysis
Although starting dialysis is a life changing event, the goal is to have you leading as normal and active a life as possible. The type of dialysis that is right for you will depend on how you live your life, and where you live.
Dialysis can often be done at home and overnight, but depending on individual needs some dialysis may also be required during the day. This allows most people to continue to:
- play sport and exercise
- maintain a balanced diet
- keep social engagements
- have intimate relationships
- travel and take holidays
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Last reviewed: March 2020