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? And is one better than the others? There are four main ...

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.

Blood – everyone's got it. In fact, an adult who weighs between 150 and 180 pounds has around 1.2 to 1.5 gallons of blood in their body. This makes up approximately 10% of an adult’s weight. Blood ...