Dialysis is a mechanical process that partly does the work that healthy kidneys would do. Hemodialysis uses a man-made membrane (dialyzer) to filter wastes, remove extra fluid from the blood, restore the proper balance of chemicals in the blood, and eliminate extra fluid (edema) from the body.

Before hemodialysis treatments can begin, a doctor will need to create an access where blood can flow in and out of the body (dialysis access). This is usually done by joining an artery and a vein in the forearm or by using a small tube to connect an artery and a vein.

Hemodialysis is usually done in a hospital or dialysis centre on a set schedule. It is usually done 3 days a week and takes 3 to 5 hours a day. In some cases, hemodialysis can be done at home. Home hemodialysis can be done on more days of the week. Some types of home hemodialysis are done during the night.