Ideally, a kidney transplant should be performed when tests show that the extent of damage to your kidneys is so great that you'll need dialysis within the next 6 months.
However, because of the lack of available kidneys, it's unlikely you'll receive a kidney donation at this time, unless a family member or friend who has a similar tissue type is willing to make a living donation.
Most people with kidney failure need dialysis while they wait for a donated kidney to become available.
The average time a person spends on the waiting list for a kidney transplant is 2 and a half to 3 years, although it can be shorter or longer than this.
Demand for donations from recently deceased people far outstrips supply, so there are strict but necessary guidelines about how donations are allocated.
Children and young adults are generally given priority if a matched donation becomes available, as they'll most likely gain a longer-term benefit from a transplant.
For older adults, a scoring system is used to determine who should get a donation. The score is based on factors such as how long you've been on the waiting list and how well matched the donor is in terms of tissue type, blood group and age.
If you're on the waiting list for a kidney, the transplant centre will need to contact you at short notice once a kidney becomes available, so you must inform staff if there are any changes to your contact details.
You should also inform staff if there are changes to your health – for example, if you develop an infection.
While waiting for a donated kidney to become available, it's important to stay as healthy as possible by:
Make sure you always have an overnight bag ready for when the call comes, and make arrangements with friends, family and work so you can go to the transplant centre as soon as a donor kidney becomes available.
In England, there are 20 NHS specialist kidney transplant centres; 6 in London, and the rest in the following 14 cities:
Read more about kidney transplant units on the NHS Blood and Transplant website.