FAQs: Whole Blood Donations
For questions related to COVID-19, see our COVID-19 page for details.
How much blood do you take with each donation?
We collect about 450 ml (a pint) of blood during a single blood donation.
How long will it take my body to replace the blood that’s taken?
The plasma portion of your donation is replaced within hours and the platelet portion within days. Red blood cells can take months to replenish.
How long after donating blood should I avoid strenuous activity?
You should avoid strenuous activity for six to eight hours and heavy lifting for 24 hours after giving blood.
Are there times when I should contact Canadian Blood Services after I’ve given blood?
Yes. Please call us if you:
- Forgot to inform us about any health changes, lifestyle changes or travel history
- Decide that your blood should not be used
- Experience adverse reactions (e.g. fainting or pain in your arm) after you leave the donor centre
- Develop diarrhea or get sick within a week of your donation
- Are diagnosed with West Nile Virus or Zika Virus within 14 days of your donation
- Test positive for Hepatitis or HIV within 12 months of your donation
It can take between 6 to 8 weeks to receive your donor card via Canada Post.
If you have not received your card 8 weeks after your first donation, please do not hesitate to contact us again. You can call us toll free at 1 888 2 DONATE (1-888-236-6283) and a customer service representative will be happy to assist you.
You can still donate blood without your Canadian Blood Services donor card since your donor information is on file. Simply bring ID that is government-issued with your full name and date-of-birth to the blood donor centre.
Obtaining a replacement card
You may reorder your card the next time you donate at your local blood donor clinic. Simply bring ID that is government-issued with your full name and date-of-birth to the blood donor centre. If you are a recent donor, simply call us at 1 888 2 DONATE (1-888-236-6283) and we can help you over the phone.
Unfortunately, Canadian Blood Services is unable to issue donor cards to people who no longer donate blood.
For someone to be a ‘universal’ donor, what blood type must he/she have?
People with O-negative (O-) blood are considered universal donors because anyone can receive O- blood. But all blood types are needed to meet the needs of patients for blood and blood products.
I am currently taking medication. Can I still give blood?
If you want to know whether a particular medication might keep you from being eligible to donate, you can call us at 1 888 2 DONATE (1-888-236-6283). You can still give blood when taking certain medications: in many cases, it isn’t the medicine but rather the reason for taking it that may be of concern.
Why are the questions asked during the screening process so personal?
The screening process is lengthy and may seem intrusive, but it is absolutely necessary to ensure your safety and safeguard the blood supply by screening out people who are at greater risk of transmitting infections through their blood. The criteria we use to determine donor eligibility are based on risk factors. All our screening measures meet stringent regulatory requirements and accepted worldwide blood service standards.
If you test all donated blood, is screening even necessary?
While we test every donation using sophisticated and reliable procedures, these tests are not perfect. There are brief periods after infection called ‘window periods’ when current tests cannot detect signs of a virus. Advances in testing technology have reduced but not eliminated these window periods. Therefore, we have strict screening procedures to ensure each donor poses the least possible risk of transmitting diseases through his or her blood.
I donate blood regularly and my answers to the screening questions are always the same. Do I have to answer every time I donate?
Because a lot can happen between donations, we are required to treat every donation as a separate event. For the safety of the blood supply and potential blood recipients, we must take maximum caution and ask questions every time.
I am a healthy teenager. Why do I have to wait until I’m 17 before I donate?
Canadian standards for blood donation dictates that 17 is the earliest age at which you can donate blood. There are other ways to give. Find out how you can get involved by becoming a volunteer or peer leader - organizing a high-school blood donation events - by emailing us at email@example.com or calling 1 888 2 DONATE (1-888-236-6283).
May I bring children with me when I come to donate?
Please plan to have a friend or family member who is not donating with you if you bring children under 10 years of age. Children under 10 and their supervisor are welcome to wait in the refreshment area and enjoy a snack while they wait for their hero/donor. We ask that children in our clinics be supervised by a person who is at least 12 years of age.
Children aged 10 and older are welcome to wait in the refreshment or designated waiting areas without supervision.
Please ensure those joining you are comfortable being in an environment where blood is collected.