What Is the Universal Recipient Blood Type?

Why AB+ Blood Type Is Compatible With All Others

In This Article

People with AB+ blood type have the only blood type that is compatible to receive blood transfusions from donors with any of the eight blood types: O+,O-, A+, A-, B+, B-, AB+, and AB-. This is why a person with AB+ blood type is called a universal blood recipient. A universal blood donor has type O- blood. Matching the correct blood type is critical to a successful blood transfusion or organ transplant and the patient's life. If a person receives incompatible blood during a transfusion or organ donation, the body treats the donor cells as foreign invaders. This triggers the immune system to attack the donor cells instead of incorporate them into the body. An immune system attack can lead to bigger problems. A large activation of the immune and clotting systems can cause kidney failure, shock, circulatory collapse and rarely death. Antigens and proteins, called Rh factor, play a major role in blood and organ recipient compatibility with a donor.

What Makes a Universal Blood Recipient?

People with AB+ blood type have the only blood type that is compatible to receive blood transfusions from donors with any of the eight blood types: O+,O-, A+,A-, B+, B-, AB+, and AB-. This is why a person with AB+ blood type is called a universal blood recipient.

What Is a Universal Blood Recipient?
Verywell / Emily Roberts 

Blood Types

Antigens determine how a blood recipient reacts to a blood transfusion. An antigen is any substance that the immune system can respond to. If the immune system encounters an antigen that is not found on the body's own cells, it will set off an attack to fight that antigen. Antigens that are found on the body's own cells are known as "self-antigens," and the immune system does not normally attack these. Antigens that are present in most blood types are as follows:

  • O blood types are unique in that they have no antigens. O- blood is considered the universal blood donor type because it is compatible with all A, AB, B, and O blood types.
  • If you have blood type A, you have an antigen that is specific and unique to A blood.
  • If you have blood type B, you have a B antigen.
  • The AB blood type means that both of the antigens for A and B blood are present. It is the rarest blood type. A person with AB blood has all of the antigens that are possible.

Universal Blood Recipient vs. Universal Blood Donor

Type AB+ is the universal blood recipient type. But type O- is the universal blood donor type. Anyone with this blood type can donate blood to a person in need regardless of their blood type.

In addition to antigens, blood has a protein factor called Rh factor, which is positive (present) or negative (not present). This is why you will see a + or - attached to a person's blood type. Rh-negative blood is given to Rh-negative patients, and Rh-positive or Rh-negative blood may be given to Rh-positive patients. Since both A and B antigens are present in a person with AB+ blood and it has a positive Rh factor, the recipient won't reject the blood. The body identifies that blood as part of itself rather than being foreign and wanting to reject it.

Blood Transfusion Reactions

There is a difference between a reaction caused by transfusing the wrong type of blood—which can rarely be fatal—and an allergic reaction to the blood transfusion, which is possible regardless of blood type.

A hemolytic transfusion reaction can occur when there is a mismatch between A, B, and O blood types of the donor and recipient. Antibodies in the recipient's blood attach to the donor red cells, and they are then destroyed in the recipient's bloodstream, liver, and spleen. This can lead to jaundice and may cause uncontrolled clotting in the bloodstream, shock, and rarely death. Hemolytic transfusions reactions are divided into two categories: acute and delayed hemolytic reactions. Acute reactions happen within 24 hours of a transfusion and delayed reactions occur after 24 hours. Delayed reactions may happen two weeks to 30 days after a transfusion. Since hospital blood banks type and crossmatch each unit of blood to be given to a recipient, these reactions are rare.

An allergic reaction to a blood transfusion is not caused by a blood type mismatch. It is caused by the recipient's body identifying the blood as a foreign invader.

The immune system then attempts to destroy the foreign cells. Also known as an acute non-hemolytic transfusion reaction, this type of reaction results in itching, fever, chills, itching, and a rash. It often passes in 24 hours to 48 hours and is treated by stopping the transfusion and administering a dose of Benadryl or another histamine-reducing agent to reduce the reaction.

Unlike the reaction that happens when a person receives the wrong blood type, the reaction the body has to the blood that is identified as "foreign" can be treated effectively. 

A person who has a severe type of reaction to a blood transfusion may require more thoroughly screened blood in the future to prevent a similar reaction with subsequent transfusions.

Organ Donation

Receiving a blood transfusion is not the only time that being a universal blood recipient matters. A person who needs an organ transplant could also potentially benefit from being a universal recipient.

A patient who needs an organ and has AB+ blood type can accept an organ from donors of all blood types, just as they can accept blood of any type. However, the process of matching a donor and recipient is more complicated than only matching blood type.

The organ allocation system is also set up so that the distribution of organs is fair. That way, people with AB blood don't receive an unfair percentage of organs while recipients with other blood types receive fewer. 

A Word From Verywell

Individuals with AB+ blood are able to accept blood from donors of all blood types. While this is an interesting fact, there is typically an adequate blood supply for anyone with a need—regardless of their blood type—on any given day. 

Blood donations from a generous community make it possible for a patient of any blood type, rare or otherwise, to benefit from a transfusion of blood when needed.

This article was originally written by Jennifer Whitlock, RN, MSN, FN.

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