Dialysis blocks the passage of larger substances (for example, red blood cells, large proteins). This replicates the filtering process that takes place in the kidneys when the blood enters the kidneys and the larger substances are separated from the smaller ones in the glomerulus. The two main types of dialysis, hemodialysis and peritoneal dialysis, remove wastes and excess water from the blood in different ways. Hemodialysis removes wastes and water by circulating blood outside the body through an external filter, called a dialyzer, that contains a semipermeable membrane. The blood flows in one direction and the dialysate flows in the opposite.
Organ donation blood due to their interpretation of the Hebrew Bible/Christian Old Testament as prohibiting blood transfusion, and Muslims require that the donor have provided written consent in advance. A few groups disfavor organ transplantation or donation; notably, these include Shinto and those who follow the customs of the Gypsies. Orthodox Judaism considers organ donation obligatory if it will save a life, as long as the donor is considered dead as defined by Jewish law. In both Orthodox Judaism and non-Orthodox Judaism, the majority view holds that organ donation is permitted in the case of irreversible cardiac rhythm cessation. In some cases,