Haemodialysis is a method used to filter the blood when the kidneys are not working properly. It involves the blood passing from the person's body through a tube to a machine called an artificial kidney or dialyser. The blood flows past a membrane in the machine, which allows waste products to move from the blood, across the membrane into a special fluid on the other side. The purified blood is then returned to the body.

Use of an artificial kidney to remove toxic compounds from the blood by passing it through a tube of semipermeable membrane. The tube is bathed in a dialysing solution to restore the normal chemical composition of the blood while permitting diffusion of toxic substances from the blood.

dialysis of the blood to remove toxic substances or metabolic wastes from the bloodstream; used in the case of kidney failure