Dialysis How dialysis works
 Dialysis machines work by using diffusion and ultrafiltration. A very fine material, called a membrane, allows blood and fluid to flow through it. In the machine, the blood flows in one direction, and on the other side of the membrane, a special fluid, dialysate flows in the opposite direction. Dialysate is a fluid that has different chemicals in it, such as potassium and calcium. A doctor would decide what mixture of chemicals would be needed for each patient. The dialysate has bicarbonate in it to lower the higher acid levels that these patients often have.