Before you donate

Please read all the information provided here carefully before you donate blood, plasma or platelets.

The reason for this is two-fold:
• to remind you that we rely on your honesty to keep the blood supply safe.
• to provide you with the information you need about the risks of donation so that you can make an informed decision about donating blood, plasma or platelets.

For the vast majority of people, blood, plasma or platelet donation is a simple and trouble-free experience. There are however some risks you need to be aware of. Below is a description of these adverse consequences of donation and the recorded incidences at the WBS:


Minor bruising of the arm after blood donation is common, this is usually harmless and will fade within a few days. To help reduce the chances of bruising, you will be asked at clinic to apply pressure to the venepuncture site once your donation is complete. You should avoid heavy lifting or manual work with your donor arm for at least twelve hours after donation.

Some donors experience pain in their donor arm following donation. This is quite common and after 24 hours you should use the arm normally.

Sometimes more significant bruising of the arm develops (1 in 97)2 and can occasionally cause symptoms that include nerve irritation, swelling or restricted movement. If the bruising, pain or discomfort becomes severe, or does not resolve within seven days, you should seek advice from the WBS helpline on 0800 252266, contact your GP or call NHS 111.

Arm Discomfort

Infrequently, inserting the needle may cause arm discomfort post donation (1 in 385)2 - almost all of these settle within a few weeks of donation.

Feeling Faint

Some donors may feel faint (1 in 57)2 (light headed, dizzy, hot, sweaty, trembling, shaky or nauseous), as a consequence of giving blood, plasma or platelets and a small number may actually faint (1 in 655)2. Some donors that do faint may also injure themselves during the faint (1 in 13 600)2. There are a variety of reasons for this and there are things that you and our staff can do to help reduce the risk of this happening. Please follow the advice given to you.

If you are at all concerned about feeling faint or fainting ask to speak to the nurse in charge. Our staff are trained to care for you if you do feel faint and will make sure you do not leave the clinic until you are feeling well.

Occasionally you may feel faint or actually faint quite a long time after donation, even the following day – this is known as a “delayed faint” (1 in 1920)2. If you do experience a delayed faint it is important that you ring the WBS helpline to report it.

After donation, please drink plenty of non-alcoholic fluid, avoid strenuous exercise, or heat e.g. saunas and hot baths. Also avoid any activity that may be hazardous to you or others should you start to feel weak or light headed.

If you do feel faint after leaving the session, lie down straight away and drink plenty of fluid. If your symptoms persist or you actually faint seek advice from the WBS helpline on 0800 252266, contact your GP or call NHS 111.

Rare risks associated with blood, plasma and platelet donation

Although extremely uncommon, other problems can occur and are described below.

Needle insertion (venepuncture)

  • arm discomfort persisting one year or more post donation, caused by - tendon injury (1 in 250 000)2, nerve injury (1 in 125 000)2
  • arterial puncture (1 in 31 500)2
  • complications related to an arterial puncture : arterio-venous fistula (none recorded for WBS)2, compartment syndrome (none recorded for WBS)2, brachial artery pseudo-aneurysm (none recorded for WBS)2
  • “re-bleed” (bleed from the needle insertion site after donation) (1 in 6600)2
  • Localised infection or inflammation (thrombophlebitis or cellulitis) (1 in 250 000)2
  • Deep vein thrombosis (none recorded for WBS)2


Donors are asked to declare all medical problems during the health screening process. Donors with a known history of significant heart (cardiovascular) problems are deferred from donating. Despite this there is still a very small chance that donors may have an unexpected adverse cardiovascular event during or post donation. These include:

  • Acute cardiac symptoms like chest pain (none recorded at WBS)2
  • Heart attack / cardiac arrest (none recorded at WBS)2
  • Mini-stroke or stroke (1 in 250 000)2


  • Localised allergic reactions e.g. reaction to the arm cleaning agent (1 in 9300)2
  • Gereralised allergic reactions (none recorded at WBS)2
  • Death (none recorded at WBS)2

Our staff are trained to recognise these rare complications and you will be given immediate treatment and appropriate advice. If issues relating to such an incident occur after you leave the session you should contact the WBS helpline on 0800 252266, your GP or NHS 999 or 111 for advice.

Let us know
So that we can ensure a safe blood supply for patients please inform us if you become unwell within two weeks following your donation or if you believe your blood should not be transfused to a patient.

2 - WBS performance data 01/04/2016 – 31/10/2018 (no data during this period for plasma donation but side effect profile aligns with platelet donation)

Iron Deficiency

Each blood donation contains approximately 240mg of iron and it can take approximately 4 - 6 months to replace this by eating a diet rich in iron. Young donors, pre-menopausal female donors, donors who donate very regularly and donors whose diets have a low iron content are at greater risk of developing iron deficiency. The time taken to replace iron lost in blood donation can be reduced by taking over the counter iron containing supplements e.g. multi-vitamins containing iron.

At registration for plasma or platelet donation (as part of the informed consent process) one of the nurses will spend time with you to discuss the plasma or platelet donation procedure, including the possible risks of plasma or platelet donation. Leaflets giving more detail will be available. For the vast majority giving plasma or platelets is a simple and trouble free experience. However there are some risks you need to be aware of:

Anti-Coagulant (citrate, ACD-A, Acid Citrate & Dextrose solution)

An anti-coagulant is used throughout the plasma/platelet donation process to stop your blood clotting within the plasma/platelet machine. The cyclic draw and return of blood to you during the donation process means that a small amount of the anticoagulant is returned in your blood. This will not cause you to be anticoagulated but can cause minor reactions with symptoms including tingling, vibration, restlessness, chilling and altered taste.

You should inform a member of staff if you experience any of these symptoms so appropriate actions such as pausing the machine or slowing the return flow of blood can be made. If symptoms persist or become uncomfortable we will stop your donation.

The anticoagulant solution (Citrate) creates a mild effect on cardiac muscle function during the donation, which can cause harm if an underlying heart condition is present. To safeguard you we record your pulse rate and rhythm and if necessary we will defer your donation and advise you to visit your GP for further investigations.


You may experience this during the first few cycles of the plasma/platelet donation flow. As the blood leaves the body to be processed in the donation machine it will start to reduce in temperature. This reduction in temperature may be noticed when the blood is returned, in the form of chilling or shivering.

Reduced Platelet Production

Studies have shown that regular platelet donors show a drop in their own platelet levels which is more marked in regular long term donors. This should have no implication for your health and is an expected finding.

Uncommon risks associated with plasma or platelet donation

Iron Deficiency

Regular plasma/platelet donors may become iron deficient. At each plasma/platelet donation you will lose up to 100ml of blood in the harness and sample pouch. So if you donate at the maximum frequency of 24 times a year, you could lose up to 2400ml of blood, the equivalent of 4-5 blood donations. The finger prick test we do before your donation is to check your haemoglobin level but does not indicate whether your iron stores are healthy or depleted. You cannot donate whole blood as well as being a plasma/platelet donor.

Rare risks associated with plasma/platelet donation

Air Embolism

This is the inadvertent entry of air into your blood circulation. There are safety checks in place to ensure that the risks of this occurring are as low as possible. This has not occurred at the WBS to date.

Red cell loss

Occasionally we are unable to return your blood to you - this means a loss of 200mls of your blood. This may occur if you experience a side effect whilst donating e.g. feeling faint, developing a bruise/haematoma or more rarely if there are issues with your donated red blood cells (haemolysis).


When you volunteer to give blood/plasma/platelets for the first time your details will be registered with the Welsh Blood Service (WBS). All information relating to you and your blood/plasma/platelets donation is treated confidentially and stored securely on our database in accordance with current Data Protection Legislation and our Privacy Statement.

Health Screening

The first step when you attend the donation clinic is to register you. Then, a member of our team will show you how to use the touch screen to complete the Self- Administered Health History, which will tell us about your general health and lifestyle. We want to make sure you are fit and well enough to donate blood/plasma/platelets and that your blood/plasma/platelets is safe to give to a patient.

In strict confidence a member of our staff will discuss your Self- Administered Health History with you to assess your suitability.

Haemoglobin Testing

We will take a small drop of your blood from your finger to check your haemoglobin level. If this shows you are unable to give blood today a blood sample will be offered and we will write to you and advise you what to do next.

Donor Consent

If you are a plasma/platelet donor, prior to your first plasma/platelet donation appointment, you will be asked to give informed consent to donate plasma/platelets using a cell separator machine.

After health screening blood, plasma and platelet donors will be asked to sign a declaration in the presence of a staff member. By signing you are agreeing that:

  • You have read and understood this leaflet and the other information provided.
  • You have read, understood and completed the Self –Administered Health History.
  • You understand the nature of the donation process and the possible risks involved in giving blood, as explained in this leaflet.
  • You have received satisfactory answers to any questions you might have.
  • You are, to the best of your knowledge, not at risk of transmitting HIV, hepatitis or other infections.
  • All the information provided is true and accurate, to the best of your knowledge.

And you are giving consent for:

  • The WBS to hold your details on their database in accordance with the terms of relevant Data Protection legislation. Further information is provided in our leaflet ‘Your information rights: collecting data and access to your Welsh Blood Service Record’ and the privacy notice on our website. For the purpose of blood safety, once entered onto our donor database we are required by law to retain and potentially process your information indefinitely.
  • Your blood to be tested for HIV and other conditions as listed in this leaflet and to be informed should any of these tests give a positive result.
  • Your blood to be used for the benefit of patients (either directly or indirectly).
  • The WBS to establish your blood group and if necessary your white cell and/or platelet type.
  • The WBS to store a small sample of your donation for further testing, if required.
  • The WBS to contact you directly or through a third party in order to carry out donor satisfaction surveys or other work related to service improvement.
  • The WBS to contact you during blood/platelet stock shortages to ask for your support. You may also be asked to give consent for extra tests to be performed or to allow your donation to be used for a particular purpose.
Giving Blood/Plasma/Platelets

You will be asked to sit in a donation chair where we will check your details. A pressure cuff will be placed around your arm (helps to make the vein more visible) and the needle insertion area will be cleaned with antiseptic. A needle attached to a blood bag or plasma/platelet tubing set will then be inserted into your vein. During your donation you will be encouraged to open and close your hand as this helps the blood flow smoothly.

Throughout your donation our staff will keep a close eye on you to make sure everything is fine. If there are any concerns or you are not happy to continue we will stop the donation early so it is important that you let us know.

It usually takes 5 to 10 minutes to complete your blood donation of just under a pint. It can take up to 90 minutes to complete a platelet donation and up to 50 minutes to complete a plasma donation. At the same time blood samples are taken (from the blood collected so no extra needles are needed).

After the donation the needle will be carefully removed from your arm and a dressing and bandage will be applied. During this time you will be shown how to apply pressure to the needle site as this is important in helping to prevent bruising.

After Donation

After donating blood you will be asked to rest on your donation chair for a short time to make sure all is well before you move to the refreshment area. It is important to replace the fluid you have lost so please give yourself at least 10 minutes in the refreshment area and drink up!

After donating plasma/platelets a rest is not routinely required unless indicated by yourself or a staff member. Refreshments are offered before, during and after your platelet donation.

Your blood group is checked each time you donate. We also test your blood for HIV, hepatitis B, hepatitis C, hepatitis E, syphilis and HTLV1. If your donation gives a positive result for any of these tests you will be contacted and offered further advice and your donation will have to be destroyed.

Extra tests are carried out on some donations either because of information provided by you e.g. travel history or to meet the special needs of certain patients e.g. babies. These tests may include malaria testing and more detailed blood grouping.

A full blood count is performed at every platelet donation.

1 Human T Lymphotropic Virus can cause serious blood and nervous system disease. HTLV is known to be transmissible through transfusion.

The vast majority of donations are used for patients e.g. after blood loss or cancer treatment.

We would like donors to know that their donation may also be used for purposes other than for direct transfusion to patients. This may be for quality assurance, education, training, development or authorised research, which has been approved by an ethics committee. We may also use the donation in the commercial preparation of healthcare related products within WBS or by other organisations.

The WBS will always ensure that there is no implication for your health or welfare, you will not be identifiable, and any income received by us will be used to offset WBS cost and thus represent a benefit to the National Health Service in Wales.

Some occupations/hobbies, examples listed below, can increase risk of injury should you become unwell after donating; therefore you should not donate today if, in the next 12 hours, you intend to participate in any of the following activities:

• Drive a HGV, crane, minibus, bus or train
• Emergency response vehicle driver
• Fire crew
• Climb ladders or scaffolding
• Aircrew (pilot) or Air Traffic Controller
• Work underground
• Diving
• Parachuting
• Motor sport
• Climbing

We are committed to providing a high quality service to our donors and value your feedback. You can help us to improve our service by completing a Compliments and Concerns leaflet which you will find at the refreshments area.
If you are unhappy with our service it is often best to raise the issue as soon as possible. Please ask to speak to the person in charge of the donation clinic who will try to resolve the problem with you.

Alternatively, guidance on submitting a concern can be found at or you can call us on 0800 252 266.

You can also email us at or write to us at Welsh Blood Service, Ely Valley Road, Talbot Green, Pontyclun CF72 9WB

If you have any questions about any information in this leaflet please ask a member of staff who will be happy to help.

To download a printable version of the above information please click HERE