Dialysis acts as an artificial kidney by filtering toxins, waste, and fluid from your blood through a semipermeable membrane—a material that allows fluids and small particles to flow through it, but not larger particles. The 2 types of dialysis, hemodialysis and peritoneal dialysis, use different methods to filter toxins from your body. With hemodialysis, the filtering membrane is called a dialyzer and is inside a dialysis machine. Your blood is circulated through the dialysis machine and cleaned before being returned to your body. With peritoneal dialysis, the filtering membrane is the natural lining of your peritoneum or abdomen and blood never leaves your body. Both types of dialysis also use a dialysate solution in the filtering process to help remove unwanted substances.