Dialysis is a procedure to remove waste products and excess fluid from the blood when the kidneys stop working properly. It often involves diverting blood to a machine to be cleaned.
Normally, the kidneys filter the blood, removing harmful waste products and excess fluid and turning these into urine to be passed out of the body.
If your kidneys aren't working properly, for example because you have advanced chronic kidney disease (kidney failure), the kidneys may not be able to clean the blood properly. Waste products and fluid can build up to dangerous levels in your body. Left untreated, this can cause a number of unpleasant symptoms and eventually be fatal. Dialysis filters out unwanted substances and fluids from the blood before this happens.
It depends. In some cases, kidney failure may be a temporary problem and dialysis can be stopped when your kidneys recover. But often, someone with kidney failure will need a kidney transplant. It's not always possible to carry out a kidney transplant straight away, so dialysis may be needed until a suitable donor kidney becomes available. If a kidney transplant isn't suitable for you, for example because you're not well enough to have a major operation, dialysis may be needed for the rest of your life.
In many cases, you'll be able to choose which type of dialysis you want to have. The two techniques are equally effective for most people, but each has its own advantages and drawbacks. For example:
Haemodialysis means you'll have four treatment-free days a week, but the treatment sessions last longer and you may need to visit hospital each time
Peritoneal dialysis can be done quite easily at home and can sometimes be done while you sleep, but it needs to be done every day
Many people on dialysis have a good quality of life. If you're otherwise well, you should be able to: