Medically reviewed by Amelia MacIntyre, DO One of the most important characteristics of blood is its type. Knowing your blood ...

There are eight common blood types: A positive, A negative, B positive, B negative, O positive, O negative, AB positive and AB negative. But which is the rarest? Here's what to know. Start the day ...

While everyone’s blood contains the same basic parts, there are eight different blood types. The type you have depends on genes you inherit from your biological parents. What makes your blood ...