The Welsh Blood Service - Give blood and save lives...

Giving Blood

How long does it take? - It should not take more than 15 minutes for your donation to be taken once on the donation bed. The whole process from completing the Donor Health check to having refreshments after giving blood should take no more than 45-60 minutes.

Is it painful? - For most people giving blood is a simple and trouble-free experience and staff aim to minimise any discomfort there might be. Bruising can occur but you can help reduce the chance of bruising.

Will I faint? - A few people do feel faint after giving blood but our staff are fully trained to deal with this. It is important that you are not short of fluids and have eaten your normal meals before offering to give blood. It is also important to drink plenty of fluids (not alcohol) after giving blood. We recommend you avoid unaccustomed exercise for the next few hours and that you avoid any activity that may be hazardous to you or others if you should feel weak or light-headed after your donation. If you are a smoker you should wait at least 2 hours after giving blood before having a cigarette. This is because smoking causes the blood vessels to narrow and reduces the blood supply to the brain. If you feel faint after leaving the session, you should lie down until you feel better. Call the Welsh Blood Service for advice or contact your GP if you continue to feel unwell.

Will I bruise? - Sometimes bruises develop but most are small and fade within a few days. Bruises are not usually serious and are caused by seepage of blood from the vein into the tissues of the arm. To help stop bruises you should, if possible, avoid heavy lifting or manual work with your donor arm for at least two hours after donation. If bleeding starts again, stop it by pressing firmly on the area for a few minutes. Occasionally, bruising may be severe or become painful. If this happens, you should contact the Welsh Blood Service for advice or see your GP. Very infrequently, inserting the needle may cause inflammation of your arm or irritation of a nerve. Our staff are fully trained to recognise these rare complications and you will be given immediate treatment and/or appropriate advice. If this occurs after you have left the session, you should contact the WBS for advice or see your GP.

How much blood do you take? - We aim to take just under a pint (470 mls).

How long before my pint is made up? - The fluid part is made up within hours provided you have enough water to drink. Providing you have enough iron stored in your body or have enough iron in your diet, the red cells take a few weeks to be replaced.

How often can I give? - A minimum interval of 12 weeks between donations should be observed.

Female donors who regularly attend at intervals of less than 16 weeks should be informed that they are at increased risk of iron deficiency. They should be advised to reduce their frequency of donation to an average of 16 weeks or more.

Testing Your Blood

We collect blood samples in tubes while you donate so that we can test them and check your blood group in our laboratory. We will tell you if we fail to collect enough samples to run the tests.

Which tests do we do? - We test every donation, no matter how many times you have given blood, for: HIV (the AIDS virus), Hepatitis C, Hepatitis B, HTLV (Human T Lymphotropic Virus) and Syphilis. People who carry these infections may remain healthy for many years but they can be passed on by blood transfusion and may have serious implications for both donor and patient.

Will I be told if any of my tests are positive? - Yes, we will tell you and give you any information and advice.

Extra Tests - To meet the special needs of certain patients, such as babies, some extra tests, such as for Cytomegalovirus or additional blood grouping, may be carried out on selected donations. The range of blood tests we do is under regular review and other tests may be introduced.

Unclear Reactions In Our Tests - In a few cases, donations may prove unsuitable because the donor's blood reacts against the testing chemicals that we use. There are no health implications for the donor but testing problems prevent us using the blood. This problem usually disappears within a few months. We will send you a more detailed explanation if your blood gives an unclear reaction.

Haemoglobin Levels - You need to have a high enough level of haemoglobin (the red part of your blood made from iron) before we can accept a donation from you. This is to prevent you from becoming anaemic. (Anaemia is when there is a reduction in the ability of the red blood cells to carry oxygen around the body.) Also we need to know that the blood being used for transfusion has enough haemoglobin in it to be of benefit to the patient.

The "finger prick" test estimates your haemoglobin levels. A drop of your blood is put in to a Copper Sulphate solution. If it sinks this indicates that your haemoglobin levels are high enough to donate. If it doesn't sink your haemoglobin levels are too low for us to take a donation. We then ask if you will give a blood sample so that we can check your "full blood count" in our laboratory. This will show if you are anaemic or not. Some people's haemoglobin levels are naturally lower than the minimum needed to give blood. Sometimes the finger prick test indicates that a person's haemoglobin levels are low when they are in fact OK or borderline. This happens more in the summer months when the blood in the body is more dilute.

Eligibility - Are you taking any tablets, medicines or injections? The reason you need to take medication may prevent us from taking a donation from you. Some drugs are so dilute in the blood that they will not adversely affect any patient who receives your blood. Some drugs may effect the person who receives the blood or, if they are pregnant, their unborn child. Some medication, such as aspirin and some other painkillers may make platelets less effective. We need to know if you have taken any of these within the previous 5 days of giving blood so that we don't use the platelets from your donation.

If you are taking a stable dose of beta-blockers or diuretics to treat high blood pressure you should be able to donate. This does not apply to other treatments for blood pressure so please check with us.

Additional information on eligibility is available in the UK Blood Transfusion Services Donor Selection Guidelines (this link will open a new browser window)

Foreign Travel

South and Central America - Special rules apply to people born in, or whose mother was born in South or Central America or who have spent 28 days or more in primitive rural conditions there. We need to test for Chagas' disease, which can be transmitted to humans by a nocturnal blood-sucking bug. Chagas' disease can also be passed on through blood transfusions and from mother to their unborn child. If this applies to you we will ask you to give a sample of blood first so that we can test that you do not carry this disease.

Malaria - Malaria can be transmitted through a blood transfusion. We now have a test that can tell us whether you have been in contact with Malaria. Provided that it is more than 6 months since your return from a malarial area we can take the test at the same time as a donation. A positive test result will mean that you cannot give blood for the time being and your donation will not be used. A negative result will enable us to use your donation and will be valid until you next visit a malarial area.

The following rules apply:

Visitor (less than 6 months stay in a malarial area). If you have not had an unexplained fever during your visit or within 6 months of your return we will do the test. If the visit was over 1 year ago you will not need a test.

If you have an unexplained fever during your visit or within 6 months of your return please wait 6 months from the last symptoms before offering to give blood again. We will then do the test.

If you have ever had malaria we will do the test but only if at least three years has elapsed since your last symptoms.

If you have lived in a malarial area for a continuous period of six months or more, at any time of life we will do the test if at least 6 months have elapsed since your last visit to any malarial area.

Travel to North America - If you visit any part of Canada or the USA between 1 May and 30 November you will not be able to give blood for 28 days after your return to the UK. This is to reduce the risk of transmitting West Nile Virus to patients who need blood transfusions. West Nile Virus is an infection that can be transmitted to humans by the bites of certain species of mosquito. West Nile Virus has become an increasing problem in North America during the mosquito season. The virus can be found in the blood of infected people and infections have occurred in the USA. The Welsh Blood Service does not test blood donations for this virus.

Vaccinations and Immunisations - The rules for vaccinations and immunisations vary depending on whether live or non-live viruses or bacteria are used and whether the immunisation was given for prevention or because of exposure to disease. Please check with us if you have had preventative immunisation in the 8 weeks before offering to give blood or if you have been immunised in the previous 12 months following exposure to a disease.

Blood Transfusion since January 1980 - People who have received a transfusion, or for whom there is a strong possibility that they may have received a transfusion, since January 1980 cannot give blood. This is a precautionary measure to reduce the risk of Variant Creuzfeldt Jakob Disease (vCJD) being transmitted through transfusion. For more information please visit our download section of the site to download a leaflet, or request a copy from the Welsh Blood Service.

Contact With Infectious Diseases - Recent contact with infectious diseases e.g. chicken pox means that you will need to wait until the incubation period, usually at least 4 weeks, has passed. If you are incubating an infectious disease you could pass it on to any patient who receives your blood.

Acupuncture and Blood Donation - If you've had acupuncture and it has been done by a medical practitioner registered with the General Medical Council (GMC) or by a nurse registered with the Nursing and Midwifery Council (NMC), you can donate straight away. This also applies if it has been performed by NHS staff on NHS premises. In other cases you cannot donate for 12 months unless you can give us a valid certificate from an acupuncture practitioner registered with the British Council for Acupuncture, the Acupuncture Association of Chartered Physiotherapists, the General Chiropractic Council or the General Osteopathic Council. Sample copies of the certificate can be obtained from us.

About blood and different blood groups

About Blood - Between 7 - 10% of a person's weight is blood. Weight is a good guideline for blood volume in people of average build. This is why we set a minimum weight limit of 7st 12lbs (50 kg) because if more than 13% of blood volume is taken there is more risk of the donor feeling faint after donating. People who are very overweight may not be allowed to give blood for their own safety.

Blood is a defence against infection and takes waste material to the kidneys. It carries oxygen and carbon dioxide to and from the tissues and the lungs. It gives food to the tissues and regulates the chemicals in the body and regulates the temperature of the body. Each donation of "whole blood" can be separated into red cells, platelets, plasma and white cells.

Red cells can be stored for 35 days at 4°C.They are used to replace blood loss as a result of accidents, operations or disease.

Platelets can be stored for only 5 days at 22°C. They help to prevent bleeding in people who have a low platelet count because of disease or as a result of treatment for illness such as cancer and leukaemia. Platelets are collected from whole blood donations and through a special machine method of collection called plateletpheresis.

Plasma replaces fluid in burns patients. Fresh Frozen Plasma can be stored for 1 year at minus 40°C. It replaces missing clotting factors. Clotting factors such as Factor VIII are also removed from plasma to treat patients with haemophilia and to make immunisations such as anti-tetanus. White cells need to be used within 24 hours of collection. They are used in rare circumstances to help treat severe infection that will not respond to antibiotics. All but these special donations have the majority of white cells filtered out – a process called leucodepletion.

What are the main blood groups? - These are O, A, B and AB. Each group is also classified as either Rhesus D negative or Rhesus D positive.

How did I get my blood group? - Blood groups are inherited from your parents. The four blood groups, A, B, AB and O are controlled by the A, B and O genes. The A and B genes are dominant and group O is dependent on the inheritance of an O gene from each parent. The inheritance of the Rhesus D (Rh D)gene from either or both parents results in the Rh D positive blood group "expression". The absence of the Rh D gene results in the expression of the Rh D negative blood group.

What are the most and least common blood groups? - 44% of people in the UK have O group blood; 42% have A group blood. The least common groups are B (10%) and AB (4%). 85% of the population are Rh D positive and 15% Rh D negative.

Is there one group that is extra special? - It doesn't matter how common or how rare your blood group is we still need to collect enough to have it there when patients need it. But O Rh D negative blood, a less common blood group, can be given to anyone in an emergency and is also used for transfusion into babies.

Bone marrow / Peripheral Blood Stem Cells

Donating Bone Marrow - This requires a hospital stay, usually in Cardiff, of 24 to 48 hours. A general anaesthetic is given. Marrow is usually taken from several sites at the back of the pelvic bone using a needle and syringe. No surgical incision is required.

The after effects of bone marrow donation can be tiredness and aching and stiffness around the place from where the marrow was taken. This discomfort is usually eased with mild painkillers and normally disappears over the following week or so. It takes about a week for the body to replace the marrow and most people go back to work within a week.

As with any general anaesthetic there is a small but definite risk and a thorough medical check-up is given before the donation to ensure that the donor is fit for the procedure.

Donating Peripheral Blood Stem Cells - This is an alternative to giving a bone marrow donation. A growth factor called Granulocyte Colony Stimulating Factor (G-CSF) is given to the donor. This drug is similar to a hormone produced naturally in the body. A doctor or nurse gives an injection of this drug for 4 or 5 days before the donation procedure. The drug stimulates the bone marrow to increase its production of stem cells that then spill into the bloodstream.

The stem cells are collected from the blood by a procedure called apheresis. This is the same system that is used in plateletpheresis. The blood stem cells are collected using a similar method. The machine separates the blood stem cells from the rest of the donor's blood. The blood stem cells are collected into a bag and the remainder of the blood is returned to the donor. This procedure is usually carried out in our Clinic in Llantrisant and takes up to five hours.