Healthy kidneys clean blood and remove extra fluid in the form of urine. They also make substances that keep our body healthy. Dialysis replaces the blood cleaning functions when kidneys no longer work.

In hemodialysis, your blood is pumped through a dialysis machine to remove waste products and excess fluids. You are connected to the dialysis machine through a needle in a vein that is surgically enlarged (vascular access) or through a temporary plastic catheter placed in a vein. This allows blood to be removed from the body, circulate through the dialysis machine for cleansing, and then return to the body. Hemodialysis can be done at a dialysis center or at home. When done in a center, it is generally done three times a week and takes between three and five hours per session. Home dialysis is generally done three to seven times per week and takes between three and ten hours per session (often while sleeping).

Peritoneal dialysis is another form of dialysis used to remove waste products and excess water. It works on the same principle as hemodialysis, but your blood is cleaned while still inside your body rather than in a machine by adding clean fluid to your abdomen, letting it accumulate waste products from the blood and then draining it out. It is typically done at home. Some patients can perform peritoneal dialysis continuously while going about normal daily activities (continuous ambulatory peritoneal dialysis, CAPD).