What is a Universal blood donor?

January 19, 2023

3 min read

Blood transfusions are one of the most frequently performed procedures in hospitals around the United States with more than 33,000 transfusions being given nationally. To receive a blood transfusion, donor blood must be typed and crossmatched by a team of experts and your doctor must know your specific blood type to ensure there is no adverse reaction as the blood enters your body.

In a true emergency, there may not be time to wait for typing and crossmatching to be completed. In these situations, trauma doctors rely on blood from a universal blood donor.

What is a universal blood type?

People with O negative blood are referred to as having universal donor blood. These individuals can donate blood to ALL blood types without triggering an immune system response.

O negative blood is in high demand yet in short supply as there are not enough O- blood donors with only about 7% of people having O-negative blood. Those with group O negative blood do not have A or B antigens present at the surface of red blood cells but have A and B antibodies in plasma.

Type O negative blood is the only blood type with the lowest risk to use of causing serious reactioins when there isn’t time for correct blood typing and crossmatching.

Rhesus factor and universal donors

Universal blood donors have Rh-negative blood but they are the only ABO group that can donate blood to all blood types, regardless of the recipient's rhesus factor. In those with group A, B, or AB blood, the rhesus factor must align to ensure there is no reaction whereas those with O negative blood can donate to any ABO groups, positive or negative. U

Unlike a universal donor, a universal recipient with AB blood can receive blood from all blood types, but can only donate to other AB blood types. It is the rarest blood group.

Why do blood types have to match?

The body recognizes blood cells as “self” or “invaders”. During a blood transfusion or organ donation, if the wrong ABO blood group is administered, the body will begin to immediately attack the foreign cells eventually leading to kidney failure, shock, and even death. Typing and crossmatching blood, while timely, can save your life.

Blood transfusion reactions

A hemolytic transfusion reaction occurs when the blood being transfused is not properly matched between the donor’s blood and the recipient’s blood group. When mismatched blood is administered, the body begins attacking foreign cells primarily in the spleen, liver, and bloodstream.

A reaction may be acute or delayed. Symptoms would appear within 24 hours of receiving donor blood (acute) or they could take up to 30 days to appear (delayed).

Blood transfusion reaction symptoms include:

Jaundice - yellowing of the eyes and skin due to impaired liver function
Blood is unable to clot properly
Shock
Death

It is not common for hemolytic transfusion reactions to occur in a hospital setting as universal donor blood is used when crossmatching is not available. On rare occasions, a person may experience an acute non-hemolytic reaction to a transfusion meaning the reaction is not caused by mismatched blood. It can result in itching, chills, fever, and a rash and is treated with Benadryl.

Takeaway

Universal blood donors are unique in that they can save the life of anyone through blood donation. Universal blood, or O negative blood, is in short supply as there are not enough donors available. A blood transfusion occurs every 2 seconds in the United States.

Do you know your blood type? Do you happen to have O negative, or universal blood type? Learn how you can save many lives with one donation during National Blood Donor month in January.

General information, not medical advice

This article can't account for your health history or current treatment. Talk to a qualified clinician before you change anything about your care.

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On this page

What is a universal blood type?

Rhesus factor and universal donors

Why do blood types have to match?

Blood transfusion reactions

Takeaway

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