Kidney transplantation : If a person's kidney stops functioning completely and all other treatments fail, then the process of kidney replacement is adopted, which is called kidney transplantation. The person who gives a kidney is called the donor and the person whose kidney is transplanted is called the recipient. These two people should be related to each other. The person donating the kidney must be alive or have recently died. There must be compatibility between the body of the kidney recipient and the donor because the greater the similarity between the recipient's tissue and the donor's tissue, the lesser are the chances of the kidney being rejected by the recipient body. Sometimes the immune system of the kidney recipient considers the transplanted kidney to be foreign and starts attacking the kidney, to avoid this the immune system is made inactive with special medicines. This increases the chance of the person accepting the transplanted kidney.