Add Yahoo as a preferred source to see more of our stories on Google. A person's blood type is determined by "the presence or absence of certain antigens – substances that can trigger an immune ...

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 ...

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 ...

O- blood is the universal donor type because it can be used for anyone. AB+ blood can receive any type of blood, making it the universal recipient. Blood types need to match, or the immune system will ...