Side effects can include flu-like symptoms and aching. But they’re usually mild and last just a couple of days. You’ll receive lots of information and support for how to deal with them.

On each of the four days before you donate, you will receive injections of granulocyte colony-stimulating factor (G-CSF). This is a naturally occurring hormone that increases the number of stem cells your body produces.

You’ll then come to one of our collection centres (in London, Oxford, Sheffield or Manchester), where a doctor will insert a tiny tube in your arm, draw out your blood, and pass it through a machine to collect the stem cells.

Donating only takes 4-5 hours for most people. At the end, a nurse will check how many stem cells you’ve donated. There is a chance that you’ll be asked to come back the next day to donate more.

You won’t need a general anaesthetic or to stay in hospital overnight.

You can donate your stem cells in two ways – through peripheral blood stem cell (PBSC) collection or bone marrow donation. Around 90% of people donate via PBSC collection. However, in some situations and for some conditions, a patient will need stem cells from bone marrow.

If you join our register, you must be willing to donate in either way.

The majority of people on our register never donate. Once you are on the register you have a 1 in 800 chance of being asked to donate in the next five years.

But your chance of being chosen to donate depends on your age and sex. A young man aged 16–30 has a 1 in 200 chance of being chosen to donate in the next five years.

We’ll only ask you to donate if you have a similar tissue type to someone in desperate need of a transplant.

If you’re a match and refuse, it could be devastating news for someone with a life-threatening illness. That’s why we ask you to be fully committed when you sign up.

No, you only need to join one stem cell bone marrow register. All potential donors in the UK are added to a single registry managed by Anthony Nolan. Joining more than one would cause duplication and waste valuable resources.

Anthony Nolan, The British Bone Marrow Register (operated by NHS Blood & Transplant), The Welsh Bone Marrow Donor Registry (operated by the Welsh Blood Service) and DKMS UK all recruit donors in the UK.

All these organisations add their donors to a single UK registry, the Anthony Nolan and NHS Stem Cell Registry, which Anthony Nolan manages.

They'll come back to Anthony Nolan and we find out your 'tissue type' in order to add your details to our register. Then every time someone needs a transplant, we'll compare their tissue type to yours - and to people on our register and registers across the world.

To find out more about how we work out your tissue type, head to The Science Behind Our Work.

We have changed the way we collect donor’s tissue type from taking blood samples, to taking spit samples, to now asking people to do a cheek swab to join the stem cell register.

Whichever method you sign up by, you’ll be on our register in exactly the same way and ready to potentially save someone's life. If you signed up before then there’s no need to sign up again.

No, it won’t cost you anything. It does cost us £40 to put each person on our register, though. And that’s why we continue to raise funds, so we can continue to grow our register.

If you’re a match and come to one of our collection centres in London, Oxford, Sheffield or Manchester to donate, we’ll pay all your expenses, including travel, hotel, food and loss of earnings.

Don’t be disappointed – you can support us in lots of other ways.

It costs £40 to recruit each person to our register, so funds are vital. You could raise money for us, donate money to us or take part in a fundraising event.

You can also encourage others to join our register, especially if they’re young men.