Stem cells are special cells produced by bone marrow - a spongy tissue found in the centre of some bones - that can turn into different types of blood cells.
The 3 main types of blood cell that stem cells can become, include:
red blood cells – which carry oxygen around the body
white blood cells – which help fight infection
platelets – which help stop bleeding
How many people in the UK are registered stem cell donors?
More than two million people have registered to become potential blood stem cell donors in the UK.
According to DKMS, the world's largest donor centre, 4 out of 10 people looking for an unrelated matching donor worldwide are not able to find a match.
Only 30% of all patients are able to find a compatible donor in their family.
Why are stem cell transplants carried out?
A stem cell transplant involves destroying any unhealthy blood cells and replacing them with stem cells removed from the blood or bone marrow.
Some diseases, such as leukaemia, prevent people's bone marrow from working properly.
For certain patients, the only cure is to have a stem cell transplant from a healthy donor - but it can be very difficult to find a match.
What kind of conditions can require a stem cell transplant?
Conditions that stem cell transplants can be used to treat include:
severe aplastic anaemia (bone marrow failure)
leukaemia – a type of cancer affecting white blood cells
lymphoma – another type of cancer affecting white blood cells
certain blood, immune system and metabolic disorders – examples include
severe combined immunodeficiency (SCID) and Hurler syndrome
What does a stem cell transplant involve?
There are three main ways stem cells can be harvested, these are:
from blood – where the stem cells are removed from your blood using a special machine
from bone marrow – where a procedure is carried out to remove a sample of bone marrow from the hip bone
from cord blood – where donated blood from the placenta and umbilical cord of a newborn baby is used as the source of stem cells
90% of people donate their stem cells in a painless process similar to giving blood, called peripheral blood stem cell collection.
In 10% of cases, the stem cells are collected from the back of your pelvic bone. This is carried out under general anaesthetic.
How do I become a stem cell donor?
To become a potential blood stem cell donor you just have to check your eligibility and request a swab kit.
You can register for your stem cell donor kit on these websites: