What is Blood Typing
Blood typing is a blood test that is done to determine your blood type. There are eight blood types:
- A positive.
- A negative.
- B positive.
- B negative.
- AB positive.
- AB negative.
- O positive.
- O negative.
Your blood type depends on substances, called antigens, found on your red blood cells. Blood typing looks for A, B, and Rh factor antigens.
Your blood belongs to the A group if you have A antigens, the B group if you have B antigens, the AB group if you have A and B antigens, and the O group if you have neither A nor B antigens.
If your blood has the Rh factor antigen, your blood type is “positive.” If it does not, it is “negative.”
When is blood typing done?
Blood typing is most commonly done if:
- You need to receive blood (blood transfusion).
- You and your partner want to have a baby.
- You or your partner becomes pregnant.
Why is blood typing done?
Knowing your blood type is important because most blood types do not mix (they are incompatible). Blood typing may be done:
- So that health care providers can know what type of blood to give you during a blood transfusion. If you receive blood that is incompatible with yours during a blood transfusion, your body’s immune system will try to destroy the new blood. This could make you very sick.
- To determine whether a mother’s blood and her baby’s blood will be compatible. The health care provider will look to see whether the mother or father has the Rh factor antigen. If the father has the antigen but the mother does not, the baby is at risk of having the antigen and developing a disease in which the mother’s immune system tries to destroy her baby’s cells (hemolytic disease of the newborn). If the baby is at risk, the mother may be prescribed medicine to prevent the disease from developing.
- To diagnose hemolytic disease of the newborn.