What is Your Blood Type

Do You Know Your Blood Type?

Do you know your blood type? There's a good chance you don't, and you're not alone. A surprising number of Americans don't know their blood type. However, with around 4.5 million Americans needing blood transfusions each year, knowing your blood type may be more important than you think.

Why is knowing your blood type important?

All blood is made up of the same essential elements: red blood cells, white blood cells, platelets and plasma (the liquid portion of the blood that carries the other components). But blood also contains antigens that can trigger your immune system to attack transfused blood if it isn’t a compatible type. 

What are the different blood types?

There are four major blood groups: A, B, AB and O. These are determined by the presence or absence of two antigens – A and B – on the surface of red blood cells. There is also a protein called the Rh factor, which can be either present (+) or absent (–), and this creates the eight most common blood types (A+, A-, B+, B-, O+, O-, AB+, AB-).

So, what does this really mean? Simply put, it means you have an A blood type if your blood has A antigens or a B blood type if you have B antigens. If you have both A and B antigens, then you have an AB blood type. And if you have neither A nor B antigens, then you have an O blood type.

Each of these types are then further classified based on their Rh factor. For example, some people have A positive blood while others have A negative blood, depending on whether this protein is present or absent.