Donor wellness and safety
Frequently asked questions about the blood donation process
What are the risks of donating blood, plasma or platelets?
Donating blood, plasma and platelets is very safe for eligible donors. Below are some examples of reactions experienced by a small number of donors, with information about prevention and treatment. Serious adverse reactions to blood donation, or donation of plasma or platelets, are rare.
Recommended preventative action or treatment
Allergic reaction to materials
Arm pain or numbness
Develop a bruise or redness at the needle site
Feel faint, dizzy and/or nauseated; faint and/or have muscle spasms
Before your donation
During your donation
After your donation
After your appointment, if you faint and symptoms persist, get worse, or are concerning to you, consult a health care provider. Please also report your symptoms to us by calling 1 888 2 DONATE.
Plasma and platelet donors may experience unusual symptoms such as tingling around the mouth, chills, heaviness in the chest, difficulty breathing, chest pain, back pain or general discomfort.
Rare adverse effects
See “Can donors ever experience serious harm related to blood donation?” and “What can I do to minimize risks of donating blood?” in this list of frequently asked questions.
Can donors ever experience serious harm related to blood donation?
It is very rare for donors of blood, plasma or platelets to experience serious or lasting harm related to a donation. The rate of serious adverse reactions is less than one in 10,000 donations. Examples of serious adverse reactions include:
- Lasting arm pain or numbness. The blood vessels in the arm are accompanied by nerves that can be injured by the needle during donation. Often, pain from such an injury will stop right after the donation, but in rare cases it may persist for a period of days or even months. Permanent disability related to nerve damage from a needle is exceptionally rare.
- Infection at the site of the needle insertion. To prevent infection, the skin over the vein used for your donation is cleaned with disinfectant just before the needle is inserted.
- Injuries related to falls due to fainting, such as a broken bone, dental injury or concussion. To prevent fainting, and related injuries, follow the recommendations detailed in “What are the risks of donating blood, plasma or platelets?” in this list of frequently asked questions.
Some severe complications happen much more rarely than once in 10,000 donations. These include complications related to puncture of an artery, when a needle is inserted into an artery instead of a vein. Arterial puncture happens very rarely and donor centre staff are trained to deal with this complication. The vast majority of those who experience it will suffer no lasting harm.
An exceptionally rare complication of plasma and platelet donation is development of an air bubble that blocks flow in a blood vessel. It is for this reason that the equipment continuously monitors the tubing for air bubbles. Canadian Blood Services has no recorded cases of this complication.
Donor centre staff are trained to spot signs of reactions and injury during donation, and to intervene appropriately.
What safety measures does Canadian Blood Services take to reduce the risk of harm related to donation?
Our eligibility screening helps protect the safety of our blood donors and our plasma and platelet donors as well as the safety of the blood supply. To be eligible, donors must be in general good health and meet the requirements for minimum body weight. At the donation appointment, we will check your hemoglobin to help reduce the risk of iron deficiency from donation, and your temperature to ensure you don’t have a fever (a sign of infection). We may also check your blood pressure.
When you donate blood, plasma or platelets, the needle used during your donation is sterile, used only once and then discarded. Our donor centre staff are also well trained to spot signs that you are unwell or that the donation is not proceeding as planned. The donor centre staff who oversee donations receive substantial classroom and practical training from Canadian Blood Services in addition to any prior training and experience in phlebotomy they may have.
Do blood donors become iron deficient?
Blood donors lose iron with each donation, which over time can lead to iron deficiency. Those most at risk are young donors (aged 17-25), menstruating females and frequent donors (twice a year for women and three time a year for men). But iron deficiency due to blood donation can be prevented.
If you donate more than twice a year, talk to your health care provider about checking your iron (ferritin) and taking iron supplements. Although we check your hemoglobin every time you donate, that fingerstick test may be normal even if your iron reserves are low. A diet rich in iron is also advised for all blood donors.
If untreated, iron deficiency can lead to anemia (low hemoglobin). Symptoms of anemia include fatigue and reduced exercise tolerance.
In donation of plasma and platelets, the red blood cells are returned to the donor during the donation process, reducing their risk of becoming iron deficient. However, iron deficiency may still occur over time from the loss of blood taken for testing purposes. If you donate frequently, ask your health care provider about taking iron supplements and the need to check your iron stores.
For more detailed information about iron and how donors can prevent iron deficiency, check our pages about iron and hemoglobin.
What can I do to minimize risks of donating blood?
There are many things donors of blood, plasma and platelets can do to help reduce the risk of adverse effects. Here are some top tips.
- Let us know if you are feeling dizzy or unwell at any time during your visit.
- If you experience pain or discomfort from the needle beyond the initial pinch when the needle goes in, alert a team member. Donation should not be painful.
- To help prevent fainting and injuries that can result from fainting, follow the targeted recommendations detailed in “What are the risks of donating blood, plasma or platelets?” in this list of frequently asked questions.
- Avoid strenuous exercise or activity for 6-8 hours after donating.
- Avoid heavy lifting for 24 hours after donating, to prevent any new bleeding at the injection site and worsening of any bruise.
- While donating plasma or platelets, please alert a team member if you experience unusual symptoms such as tingling around the mouth, chills, heaviness in the chest, difficulty breathing, chest pain, back pain or general discomfort. Some of these symptoms can be alleviated by slowing down the procedure.
After your appointment, consult a health care provider if:
- You faint and symptoms persist, get worse, or are concerning to you
- A bruise develops with increasing pain, swelling, tenderness, redness or onset of fever
- You have arm pain, tingling or numbness that worsens or is concerning to you
We also ask donors to report such symptoms to us by calling Canadian Blood Services at 1 888 2 DONATE.
For more information about preventing and treating adverse reactions, see “What are the risks of donating blood, plasma or platelets?” in this list of frequently asked questions.
How is Canadian Blood Services addressing the risk of COVID-19 at donor centres?
We have wellness measures in place at all our donor centres to prevent the spread of COVID-19 among donors, staff and volunteers at our sites.