Most people are familiar with the common blood groups A, B, AB and O, along with the Rh factor that determines whether a type is positive or negative. Yet new research reveals how surprisingly complex ...

An investigation into why blood doesn't always behave as doctors expect has revealed a super-rare mutation in an extremely uncommon variation of blood. Testing more than 544,000 blood samples in a ...

Add Yahoo as a preferred source to see more of our stories on Google. Scientists have discovered the rarest blood type on Earth, belonging to just one woman. Talk about a lonely hearts club. An ...

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 are different blood types: A, B, AB, and O, with each also being Rh-positive or Rh-negative. Knowing your blood type is ...

Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory. She reports on topics from maths and history to society and animals. Katie has a PhD in maths, ...

Step aside A, B, and O—there’s a new player in town. Scientists in France have just reported the discovery of a novel, rare blood type, only recorded in a single person to date. The French Blood ...

In a groundbreaking development, French scientists have identified the world’s rarest blood group, known as Gwada-negative. It's a blood group so rare that only one woman in the world is known to have ...

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.