FAQs: Whole Blood Donations

What To Know About Giving Blood

The following are some of the questions we’re asked most often about the blood donation process:

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 after giving blood.

Are there times when I should contact Canadian Blood Services after I’ve given blood?
  • You decide your blood should not be used.
  • You develop an illness or diarrhea within the next week.
  • You are diagnosed with West Nile Virus within the next 14 days.
  • You test positive for Hepatitis or HIV within the next 12 months.
Donor Card

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 a piece of identification with your name and photo, or with your name and signature, to the blood donor clinic.

Obtaining a replacement card

You may reorder your card the next time you donate at your local blood donor clinic. Simply bring a piece of identification with your name and photo, or with your name and signature. 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 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 scientific knowledge of 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. This is why 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 have to take maximum caution and ask the questions every time.

I am a healthy teenager. Why do I have to wait until I’m 17 before I donate?
May I bring children with me when I come to donate?
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