Blood types in emergencies
Why emergencies reach for O negative
When a patient is bleeding and there is no time to test their blood type, clinicians use O negative red cells because they can be given safely to almost anyone. That makes O negative the emergency default and keeps it in high demand.
O positive matters too
O positive is the most common blood type and is also used heavily in trauma care for patients who are Rh positive. Both O types carry a large share of emergency need.
Every type plays a part
Once a patient's type is known, hospitals switch to matched blood, which conserves the O negative supply. That is why donors of every type matter, not just O.
How your donation helps
Whole blood and Power Red donations from O donors directly support emergency readiness. Your center can tell you which donation is most useful for your type.
All blood types are needed. Patient needs change, and your donation center can advise what is most useful today.
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Read the full pledgeSources and review
The guidance on this page reflects published criteria from these organizations. Eligibility and procedures vary by center and country, so confirm specifics with your donation center.
- American Red Cross
- AABB (Association for the Advancement of Blood & Biotherapies)
- U.S. Food and Drug Administration, Blood Donation
- Canadian Blood Services
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- Reviewed against American Red Cross, AABB, and U.S. FDA donor guidance
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- High confidence