Dialysis is a procedure to remove waste products and excess fluid from the blood when the kidneys stop working properly by diverting blood to a machine to be cleaned. In some cases, kidney injury or kidney failure may be a temporary problem and dialysis may only be needed whilst the kidneys recover.
Often, dialysis is used as an interim measure while the patient is waiting for a kidney transplant. Dialysis may be required until such time as a suitable donor kidney becomes available. If a kidney transplant isn't suitable for whatever reason, dialysis may be needed for life.
There are two main types of dialysis: haemodialysis and peritoneal dialysis. Haemodialysis is the most familiar, which involves filtering the blood by passing it through an external filtering machine. This is usually carried out three days a week, with each session lasting around four hours.
Peritoneal dialysis uses the inside lining of the abdomen (the peritoneum) as the filter, rather than a machine. The peritoneum contains thousands of tiny blood vessels, making it a useful filtering device just like the kidneys. A thin tube (catheter) is left in place permanently just above the navel and blood and excess fluids are drained out into a bag. This procedure usually takes about 30-40 minutes and normally needs to be repeated around four times a day.
Kidney transplant is a longer term solution. Replacement kidneys can come from compatible living donors (usually close relations) or deceased donors. The availability of kidneys and other organs for transplant depends on the willingness of the public to donate and more details about how to do this can found on the NHS Choices website.