Have you ever wondered how healthcare professionals determine blood compatibility between individuals? The answer lies in the intricate blood type classification system. Essentially, blood types are vital markers that enable medical experts to assess whether two individuals' blood can coexist.
There are four major ABO blood groups: A, B, AB and O. A person’s ABO blood group depends on whether their red cells have the A and/or B antigen. Antigens are markers on the red cell surface that can trigger an immune reaction in the recipient. A person who is blood group A has the A antigen on their red cells, blood group B has the B antigen, blood group AB has both the A and the B antigen and blood group O has neither the A or the B antigen on the surface of their red cells.
In addition to the ABO blood group, a person’s blood type is categorized as positive (+) or negative (-). This refers to the presence or absence of the Rh factor on a person’s red blood cells. The Rh factor is also known as Rhesus or the D antigen type. If the Rh factor is present on the red cells, then the person is considered positive (+). Conversely, if the Rh factor is not found on the red cell surface, the person is considered negative (-).
There are eight common blood types based on a person’s ABO group and whether they are positive or negative for the Rhesus factor:
Like your eye and hair color, your blood type is inherited from your parents. Your ABO blood group depends on your parents’ ABO blood group. Whether you have positive or negative blood doesn’t factor into determining your ABO blood group. If you are blood group B you were born from parents that have one of the following combinations:
A and B
AB and A
B and B
A and B
AB and B
AB and O
B and O
Some exceptions to these common patterns may exist. Consult with your health care provider if you have questions about parentage or blood group inheritance.
Why is my blood type negative?
If your blood type is negative, then your blood cells lack the Rh protein. B-negative blood is similar to B-positive blood in that it has the B antigen on the surface of red blood cells, but does not have the Rh factor.
How rare is B-negative blood?
B-negative blood is relatively rare, with only about 1.4% of the Canadian population having this blood type.
Who can people with B-negative blood receive blood from?
People with B-negative blood can receive blood from:
Who can receive the B-negative blood type?
B-negative red blood cells can be given to people with:
Why does my blood type matter?
The right blood transfusion can mean the difference between life and death. Our immune systems are designed to know what belongs in our body and what doesn’t. If a patient gets the wrong blood type, things can go very wrong. That’s why there are very specific ways in which blood types must be matched for a safe transfusion.
How can I find out my blood type?
Every donor is tested as part of the blood donation process to identify exactly which type they belong to. Book your appointment to donate blood and find out.