A transplant is a medical procedure where a diseased or malfunctioning organ is removed and replaced with a donor organ from a person with a similar antibody profile. Most major organs, including the kidney, lungs, liver and heart can be transplanted. Other body parts, such as bone and bone marrow, can also be transplanted.
A transplant is a risky procedure for the patient, and is often either risky to the donor or impossible unless the donor is dead. For example, removal of bone marrow is usually not harmful to the donor, while heart donors clearly need to be dead. Some organs, such as the liver and lungs, can be donated in part, leaving most of the organ intact in the donor.
Because of the risk of rejection, often the best candidate for an organ donor is a member of the patient's family. However, for organs that have to be harvested from dead donors, these have to be carefully typed for genetic compatibility. For this reason, patients awaiting a donor organ have to be type matched and put on a waiting list.
Transplants involving non-family donors are generally only available to persons who are otherwise healthy. As such, older patients and patient's who have lifestyle diseases (such as alcoholism) are generally denied the opportunity for a transplant.
A transplant is often the only treatment for some conditions, such as severe congestive heart failure and kidney failure.
Transplant patients have to be treated with immunosuppressive drugs in order to keep the body's immune system from rejecting the transplanted organ. This leaves the patient susceptible to other opportunistic infections.