These factors help define the eight most common blood types: A positive, A negative, B positive, B negative, O positive, O negative, AB positive and AB negative, says the Red Cross. But of these ...

According to the American Red Cross, the most common blood type is O positive, which is the blood type for 37% of the population. The second most common blood type is A positive. There are over ...

“I like to see us busy,” he ... there are certain types of blood that are in high demand, for example O- which is considered the universal donor blood. It is the most common blood type used ...