A person's blood type is determined by "the presence or absence of certain antigens – substances that can trigger an immune response if they are foreign to the body," according to American Red Cross.

There’s more history in your blood types than you think, and it didn’t begin with humans. Here’s what we know about them, ...

Most people don’t spare a thought for their blood type unless they’re in need of a transfusion — but could yours hold secrets to your health? There are four main blood types: A, B, AB and O.

There are different blood types: A, B, AB, and O, with each also being Rh-positive or Rh-negative. Knowing your blood type is important for safe blood transfusions and organ transplants. Type ...

Your blood type just may help determine your risk for heart disease. A new analysis suggests that having blood type O conveys some protection against heart attack and stroke, while having the far less ...