The primary ethical dilemmas surrounding organ transplantation arise from the shortage of available organs. In effect, there are now more strategies than one by which the medical world acquires or procures organs for medical transplantation. In fact, the classification of donation may have different systems. Primarily, the types of donors are based on the following criteria: if the donor is dead, brain-dead or alive; if the donor has given his/her consent for procurement, or the donation is indirectly consented, or not consented; and, if the donor is compensated for the donation or uncompensated.
These classifications are actually the real sources of questions and disputes. In the case of the "amount of life" available in the donating person, we may question if it is proper for a living person to take a part of him or her and give it to another person, diminishing the donor's quality of life (such as in its scientific or medical essence) along the process. Given that the donor is dead, we may still inquire the characteristic of a truly "dead" man, for even clinical research works cannot pinpoint the actual "instance" of a person when the death of a person happens (i.e. does it happen when the heart and lungs stop, when the entire brain ceases to have activity, or just when the cognitive and rational functions, also known as "higher faculties" stop?). And even if we established the death of the donor altogether, we may still ask if we are harming the person's dignity in any way by defacing the body and not leaving it to its natural state. Hardest case of all is that of "brain dead" donors-donors that are claimed to be incapable statistically of being able to recover fully. As a general observation seen in many instances around the world, such medical findings of brain dead patients are unreliable: many brain dead or comatose patients are capable of reverting back to their original state, given time.