The names of the different types of transplants refer to the kidney donor. There are three sources of transplant organs:

Cadaveric
A cadaveric transplant is a kidney removed from someone who has died. More than 90% of transplant kidneys in the UK come from this source.

Cadaveric kidneys are only removed after a series of tests have established that the donor is brain dead. This means that the part of the brain called the brainstem, which controls breathing, has permanently stopped working. A brain-dead patient is only being kept alive by a life-support machine.

Depending on your country, your local transplant center or a regional or national agency maintains a waiting list for cadaveric transplants. (The UK Transplant Support Service Authority (UKTSSA) in Bristol maintains a national waiting list for the UK.) Each country also has its own system for matching and distributing cadaveric kidneys. An available kidney is not given to the person who has been waiting the longest, but to the patient best suited to receive it. The wait, therefore, could be one day or several years.

A patient may be taken off a waiting list if they are ill, have an infection or traveling abroad. Removal from the transplant waiting list can be temporary or permanent.

Patients who are on the waiting list may not receive a lot of notice that a kidney is available. It must be possible to contact them at all times, and they must be prepared to go to the hospital at short notice.

Once at the hospital, some final tests will be done to assure the best possible chance of a successful transplant. If the patient has a cold, for instance, he or she may be sent home, since this illness would reduce the chances of the operation being successful.

Looking after yourself while on dialysis will increase your chances of being fit for a transplant when the right kidney becomes available.

Living donation
In a living donation, one of a donor's two healthy kidneys are removed. This kidney is transplanted into the kidney patient. A donor who is fit and well before the operation will be able to live a completely normal life with the remaining healthy kidney. The most successful transplants come from living donors. Such donations account for less than 10% of all kidney transplants performed in the UK. Living donors, may either be related or unrelated to the transplant recipient.

Living related transplant
In living related transplants, a living relative donates a kidney for transplant. A living related transplant is more likely to work than a cadaveric transplant because it is more likely to be a better match than from an unrelated donor.

The relative needs to consider the decision to donate a kidney very thoroughly especially since there is no guarantee the transplant will work. Most donors and recipients receive in-depth counseling before a final decision is reached.

If a kidney patient has a relative who is at least 18 years old, healthy, and willing to donate a kidney, they should speak to the transplant coordinator at their unit. A number of tests will then need to be arranged for both the patient and the donor.

Living unrelated
Sometimes an unrelated person will donate a kidney for transplant. It is usually someone close to the patient, such as a husband, wife, partner or close friend.

Before a living unrelated transplant can take place, an agreement must be obtained from a government body called ULTRA (Unrelated Live Transplant Regulatory Authority).

It is illegal in many countries to buy or sell organs.

As with a living-related transplant, both the donor and recipient will be given a number of tests and will receive in-depth counseling.