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 are not 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.
