Why we ask some people not to give blood

This leaflet aims to explain why we ask some people not to give blood, and how this improves the safety of blood transfusion.

The UK Blood Transfusion Services, are responsible for making blood transfusion in the UK as safe as possible for all patients. We follow strict rules and regulations when collecting and processing blood to make sure we supply the safest possible blood.

There are, however, two main areas that affect blood safety.

1. Selecting ‘safe’ donors
2. Testing every donation

Selecting ‘safe’ donors means that we have to ask some people not to donate their blood for various lengths of time, sometimes for the rest of their lives. This could be for many reasons, including their lifestyle, and their medical or travel history.

There are over 450 rules guiding donor selection and every time you come to donate you will be asked a few general questions about your health and lifestyle. Blood donors play a crucial part in maintaining the safety of the blood supply by being open and honest with their answers to these questions.

Some questions may seem strange and difficult to understand. This leaflet provides some information about why we have these rules.

Principles of selecting donors

We know people who volunteer to donate blood do so with the very best of intentions, but unfortunately there are many groups of people who, for various reasons, we ask not to donate either for a short period of time or forever.

This request can be very upsetting to some people and so our decisions are not taken lightly. They are based on the information and research that is available to us about different experiences (including travel abroad) and lifestyles, and about the effects our policies will have on patients who need blood.

People who we ask not to donate blood have the right to a clear explanation and this leaflet aims to explain some of our rules.

The aims of selecting donors are to

1. select donors whose blood, as far as we can tell, is unlikely to transmit any infection to patients; and
2. collect enough blood to meet patients’ needs.
3. make sure that donors themselves come to no harm through giving blood.

We have to balance these aims while also keeping the selection process clear and simple. We review and change the rules when necessary as the evidence on which they are based changes.

Why can some people never give blood?

Some groups of people may be at increased risk of blood-borne infections that could harm patients. For example, injecting drugs is known to be associated with an increased risk of blood-borne infections so we ask anyone who has ever injected drugs never to give blood. We test all blood donations for some important infections for example, HIV, hepatitis B and C and syphilis. However, no testing process can be perfect. We may miss infected donations because of the ‘window period’ between getting an infection and the test showing a positive result. There is also always a very small risk of mistakes being made in the laboratory.

There are many other infections for which no suitable tests exist. To reduce the risk of passing on these untested infections we rely on you to answer our questions accurately.

Why are some people told not to give blood for at least 12 months?

People who have had an ‘experience’ known to be associated with an increased risk of certain infections may be asked to wait 12 months before donating eg :tattooing or heterosexual sex with a high risk partner . This gives an apparently healthy donor plenty of time to either clear the infection or develop strong markers in their blood that our tests will usually detect.

Often the ‘experiences’ treated in this way are quite common among all donors, or among donors with rare blood groups, and banning all these donors for life would reduce the blood supply too much.

This rule applies to people who have had a heterosexual partner who may have been sexually active in a country where heterosexual transmission of HIV is common.

Why am I sometimes accepted but at other times asked not to give blood?

This may be because something has changed in your lifestyle, or because our rules or testing procedures have changed. It may also be that there is more demand for some blood types, in which case we call donors with these blood types more often.

If I am asked not to give blood, does that mean that you think I have an infection?

No. Most people we ask not to give blood are not carrying harmful infections, but our questions may identify that they are at an increased risk of carrying a blood-borne infection. We prefer not to take the risk.

Can I give blood if I have a negative HIV result from my doctor?

Not necessarily. This is because we need to select donors who have no known increased risk of blood-borne infections in general. It may be possible to give blood after a detailed consultation with one of our senior doctors.

Are there ever any exceptions to the rules?

Our selection procedure screens out people whose experiences may mean that they have an increased risk of carrying a blood-borne infection. Some people in these groups will have very low risks and their blood would probably be safe to give to patients, but it is safest to ask everyone in these groups not to give blood.

If you think you are affected by these restrictions, but feel that they do not strictly apply to you, please ask to speak to a member of our staff. It may be possible to make exceptions very occasionally, but please discuss this with us first.

If this leaflet has not answered your questions please see the list of contacts for further information.