Do you know your blood type? Scientists say everyone should in case of a life-threatening event that results in a need for a blood transfusion. But now, they've discovered a new group of blood types ...

Blood types are a classification of blood based on the antigens present in red blood cells. In the United States, O-positive is the most common blood type, and AB-negative is the rarest. A blood ...

Blood transfusions save lives. In the US alone, people receive around 10 million units each year. But blood banks are always short in supply—especially when it comes to the “universal donor” type O.

A hypersensitivity reaction happens when the immune system mistakenly identifies harmless substances as harmful. There are several types of hypersensitivity reactions, depending on the class of ...

Different blood types are prevalent in different parts of the world. In the United States, AB-negative is the rarest blood type, while O-positive is the most common. Your blood type is based on ...