The Kidney Foundation of Canada


Hemodialysis means “cleaning the blood” and that’s exactly what this treatment does. Blood is withdrawn from the body by a machine and passed through an artificial kidney called a dialyzer.

There are several different kinds of dialysis machines, but they work in almost the same way. A dialyzer (artificial kidney) is attached to the machine. The dialyzer has two spaces: a space for blood and a space for dialysis fluid. Dialysis fluid is a special liquid which helps remove waste products from the blood. The two spaces in the dialyzer are separated from each other by a very thin artificial membrane. Blood passes on one side of the membrane and the dialysis fluid passes on the other side.

Each hemodialysis treatment normally takes four to five hours. Some people call a treatment a “run”. Usually, you need three treatments (or “runs”) a week. However, certain people may need more frequent treatments or longer treatments. Sometimes shorter treatments are sufficient.

Hemodialysis is done in a hospital dialysis unit where nurses, nephrologists and other medical support staff are available. Once a patient on hemodialysis is stable, it may be possible to have hemodialysis treatments in a clinic away from the hospital, in a self-care centre (with some help from the staff), or at home. Special training is needed for self-care or home hemodialysis. Not all types of treatment are available in all communities.

Hemodialysis – strengths and limitations


  • Relieves symptoms of uremia
  • Works quickly and efficiently
  • Requires at least three treatments a week, each four to eight hours
  • Most people have suitable blood vessels for establishing an access site


  • You will have to take medications, learn new food choices, and restrict your intake of fluids
  • Access to the bloodstream is with needles, which some people find difficult
  • You must plan your week around your hemodialysis schedule (although with home hemodialysis, you can plan your treatment schedule around your week)
  • You may need to travel some distance to the hemodialysis unit
  • Some people do not have suitable blood vessels for establishing an access site