Frequently Asked Questions – Donors
- How much blood is taken during a blood donation?
- How long does it take to replace the whole blood given during donation?
- How long after donating blood should a donor avoid strenuous activity?
- Under what circumstances should I contact Canadian Blood Services after donating blood?
- For someone to be a universal donor, what blood type must he/she have?
- I am currently taking medication and I don’t think I should donate. What medications are acceptable?
- Why are the questions asked during the screening process so personal? Aren’t they discriminatory?
- If you test the blood that is donated, why do you have such a lengthy screening process?
- I am a regular blood donor and my answers to your screening questions are always the same. Why do I have to complete the screening process each time I donate blood?
- Can I give blood if I have Herpes 2 (Genital Herpes)?
- I am a healthy teenager. Why do I have to wait until I am seventeen before I donate?
- I am a healthy 70 year-old who has donated blood for many years. Why must I now provide a medical assessment form each year to continue donating when I reach 71?
- What is bone marrow?
- What diseases are treated with bone marrow transplants?
- How does the Unrelated Bone Marrow Donor Registry (UBMDR) work?
- Why are so many potential donors required?
- What do you mean by a "bone marrow match"?
- Who can join the Registry?
- Does giving blood help those in need of bone marrow?
1. How much blood is taken during a blood donation?
Approximately 450 mL (1 pint) of blood is collected during a blood donation.
2. How long does it take to replace the whole blood taken during donation?
The plasma portion of a donation is replaced within hours, the platelet portion within days and red blood cells in about 56 days. This is why blood donors cannot give more often than once every 56 days.
3. How long after donating blood should a donor avoid strenuous activity?
Donors should avoid strenuous activity for about 6-8 hours after donating blood.
4. Under what circumstances should I contact Canadian Blood Services after donating blood?
Please call Canadian Blood Services if:
- You decide your blood should not be used after donating.
- You experience fainting or bruising after leaving the blood donor clinic.
- You suffer from any illness or diarrhea within the next week or have symptoms of West Nile Virus within the next 14 days.
- You have a positive test for hepatitis of the AIDS virus within 12 months
5. For someone to be a universal donor, what blood type must he/she have?
People with O Rh negative blood are considered universal blood donors because patients of all blood types can receive O Rh Negative blood. It is important to remember that all blood types are needed to meet the needs of patients for blood and blood products.
6. I am currently taking medication and I don’t think I should donate. What medications are acceptable?
If you are taking medication and wonder whether or not you can donate, please contact your local blood donor clinic. You can still give blood when you are taking some types of medications. In many cases, it is not the medication itself that will prevent you from giving blood, but rather why it is being taken. If you have any other questions about giving blood while on medication, or about an existing medical condition, please contact our nursing staff at your local blood clinic.
7. Why are the questions asked during the screening process so personal? Aren’t they discriminatory?
Donor screening procedures are exclusionary—they exclude people who are at risk of diseases transmissible by blood. The criteria that Canadian Blood Services uses to determine the eligibility of blood donors are based on scientific knowledge of risk factors. Screening out people at greater risk of transmitting blood borne infections is necessary to safeguard the people who receive donated blood. All screening measures must meet stringent regulatory requirements and keep pace with the accepted standards of blood services world-wide. While the screening process is lengthy and may seem intrusive, it is absolutely necessary to safeguard the blood supply.
8. If you test the blood that is donated, why do you have such a lengthy screening process?
Canadian Blood Services does test every donation using sophisticated and reliable procedures. While these tests are highly effective, they are not perfect. There are brief periods after infection, known as the “window-period”, during which current tests cannot detect signs of a virus. Advances in testing technology have reduced but not eliminated these window periods. This is why Canadian Blood Services has strict donor screening procedures to ensure that each donor presents the least possible risk of transmitting diseases through their blood.
9. I am a regular blood donor and my answers to your screening questions are always the same. Why do I have to complete the screening process each time I donate blood?
The minimum period between whole blood donations is 56 days. For many donors, that time can be much longer. Because a lot can happen in 56 days, or between donations, Canadian Blood Services is required to treat every donation as a separate event. Answering the questions takes time because they are so detailed. Well-meaning blood donors could easily forget some seemingly insignificant detail. If that detail happened to be a risk factor, abbreviating the screening process could have disastrous consequences.
Can I give blood if I have Herpes 2 (genital herpes)?
A person cannot donate blood during the first 12 months of having Herpes 2. After one year of a primary occurence of Herpes 2, a person may be eligible to donate blood.
11. I am a healthy teenager. Why do I have to wait until I am seventeen before I donate?
Currently the minimum age for donation is 17 as current medical information tells us that 17 is the earliest age to safely donate. We have this regulation in place because the safety of the donor is extremely important to us. If you would like information on how you can become a volunteer or how to organize a high-school blood clinic, please contact your local donor clinic.
12. I am a healthy 70 year-old who has donated blood for many years. Why must I now provide a medical assessment form each year to continue donating when I reach 71?
To continue to donate after your 71st birthday, donors must have given within the last two years and provide an annual medical assessment that is valid for one year from date of acceptance by Canadian Blood Services. The medical assessment form is valid for one year.
Canadian Blood Services and Health Canada have agreed that these donors must have an annual assessment by their own physician, in addition to the usual extensive screening that our donors undergo. This requirement is in place to ensure the safety of the donor.
Regular donors seeking to continue donating after their 71st birthday are asked to contact Canadian Blood Services at 1 888 2 DONATE (1-888-236-6283) for more information.
13. What is bone marrow?
Bone marrow is the tissue found in the soft centre of your bones. It manufactures red blood cells (which carry oxygen), white blood cells (which fight infection), and platelets (which help to stop bleeding).
14. What diseases are treated with bone marrow transplants?
A wide variety of diseases and disorders are treated with bone marrow transplants, including blood-related diseases, such as leukemia and aplastic anemia, as well as immune system and metabolic disorders.
15. How does the Unrelated Bone Marrow Donor Registry (UBMDR) work?
For a person in need of bone marrow, the Canadian Blood Services Registry is a lifeline to more than 6.5 million potential donors. More than 210,000 of these are Canadians who have generously joined the Canadian Blood Services' Registry, while the rest belong to similar registries in other countries.
When a Canadian physician decides that a patient's best chance for recovery is a bone marrow transplant, Canadian Blood Services is able to search more than 50 registries for a compatible donor. More than 100 Canadians receive bone marrow transplants in this way every year.
16. Why are so many potential donors required?
A perfect bone marrow match isn't always available. In fact, in extreme cases, the odds of a match may be as little as one in 750,000 or less. The goal of searching bone marrow registries is to find the best available unrelated matches, giving patients the greatest possible chance of a positive outcome. And the only way to find these matches is to search a large pool of potential donors with varied ethnic and racial backgrounds. One of Canadian Blood Services' priorities is to increase the ethnic diversity of the Registry by encouraging people of varying ethnic origins to consider volunteering to donate bone marrow.
17. What do you mean by a "bone marrow match"?
Donors and patients are matched according to the compatibility of inherited genetic markers called Human Leukocyte Antigens (HLA). Six specific antigens are critical in the matching process. Of these six antigens, three are inherited from each parent.
18. Who can join the Registry?
Canadian Blood Services has established eligibility criteria to ensure that bone marrow donation is a safe procedure for both donors and recipients. We have also established Recruitment Guidelines to ensure that efforts to promote the Registry are consistent with international standards.
To join the Registry, you must be aged 17 to 50, healthy, and willing to donate bone marrow to anyone in need. Health problems that could make you ineligible include some heart conditions, cancer, blood diseases, and insulin-dependent diabetes.
19. Does giving blood help those in need of bone marrow?
Yes. Bone marrow recipients often need a large quantity of blood before and after they receive a transplant. To find a blood donation clinic near you, call 1 888 2 DONATE (1 888 236-6283).