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 ...

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.

To say that blood is vital is a huge understatement. It flows through the organs that make up the circulatory system — the heart and blood vessels and veins — delivering oxygen, nutrients, and ...

Add Yahoo as a preferred source to see more of our stories on Google. For decades, most of us thought blood types were simple: A, B, AB, or O—each with a positive or negative Rh factor. But that’s ...

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 know their blood type—A, B, AB or O—along with whether they are Rh-positive or negative. But these familiar categories (those letters plus "positive" or "negative") represent just two of ...

There are rare blood types beyond the eight most common ones, and researchers have discovered one more that brings the total count to 49. Blood type A(B) is caused by a four gene mutations and was ...

A man with a rare blood type who made his 100th donation this year is encouraging others to give blood. Robert Boocock, from York, has been donating his rare B-negative blood for 40 years, after being ...

In 2011, a woman from the French overseas region of Guadeloupe underwent routine tests before a surgery. Strikingly, doctors could not identify her blood group, which was so unique that they did not ...

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.