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.

Haemodialysis
Haemodialysis is the most common type of dialysis and the one most people are aware of.

During the procedure, a tube is attached to a needle in your arm. 

Blood passes along the tube and into an external machine that filters it, before it's passed back into the arm along another tube.

At dialysis centres, this is usually carried out 3 days a week, with each session lasting around 4 hours.

It can also be done at home. Some examples of a home dialysis schedule include:

4 times a week for 4 hours
5 times a week for 3 hours
6 days a week for 8 hours overnight