A kidney transplant is surgery in which a person who has permanent kidney failure receives a healthy kidney from another person. This single, healthy kidney takes on the workload of both of the person's failed kidneys. The failed kidneys usually are left in place. The new kidney is added to the abdomen.
The new kidney can come from a living or dead donor. A living donor is often a close blood relative of the person who receives the new kidney (the recipient). However, in certain cases, a recipient's spouse or friend can be a kidney donor.
A kidney donor must be a good match for the recipient. This means that the donor and recipient have similar chemical characteristics, called antigens, on their body cells. When these antigens match, there is less risk that the recipient's immune system will see the donor's kidney as a foreign object and reject it.