What's Your Blood Type?

You are born with a specific blood type, and you can’t change it. However, it is worth knowing what your blood type is and how it can impact your life.

Blood types are based on the markers, or antigens, on the surface of red blood cells. Two major antigens are the A and B antigens. Another surface antigen is Rh. Blood typing detects the presence or absence of these antigens, determining your blood group and Rh type.

People who have red blood cells with A antigens are in blood group A, and people with B antigens are in blood group B. Those who have both A and B antigens are in group AB. If you don’t have either of those antigens, you are in blood group O.

Your blood is Rh+ (positive) if the Rh protein is present on your red blood cells. If there is not Rh protein, your blood is Rh- (negative).

Learning your blood type

You can find your blood group and Rh type several ways.

• Ask your parents or doctor. They may have past medical records that include this information.
• Ask your doctor to order an ABO/Rh test.
• Give blood. When you donate blood, your blood type is tested as part of the process, and you have access to the information.

How your blood type impacts you

Your blood type helps to determine the types of blood that you can safely receive in an emergency, such as when you are in an accident and have excessive blood loss. Receiving a blood type that is not compatible with your own blood type could lead to a dangerous immune response and result in serious complications.

Your blood type can also help identify and match organ or tissue transplant donors with recipients. 

If you are pregnant, it is important to ensure that the Rh typing of the woman and the fetus are compatible. Otherwise, an antibody can form, which may result in hemolytic disease. Hemolytic disease is a blood disorder in a fetus or newborn, and it can be very dangerous. If this happens, the mother may need an injection of Rh immune globulin during the pregnancy and again after delivery to ensure the safety of future children.

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