(via Be Smart) Across life on Earth, blood comes in red, blue, green, purple, even clear. But why? And what makes your blood different from mine? This video will teach you everything you need to know ...

More than 100 years ago, Dr. Karl Landsteiner discovered that not all red blood cells are alike. He found that, when different people's blood was mixed, it would often clump up and curdle, destroying ...

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.

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.

Understanding blood type compatibility is necessary for ensuring safe blood transfusions and organ donations. We will explore the different blood types, how they are compatible with each other, and ...