There is one blood type that’s the “universal donor”
Type O- blood is in extremely high demand at hospitals—not just because it’s one of the rarest blood types, but also because it’s the “universal donor.” Because O- is Rh-negative, it can be given to people with both positive blood types and negative blood types.
These folks can also donate to A, B, and AB blood types. Though a foreign antigen could cause the body to attack, there are no antigens present in type O blood, so there’s nothing to attack.
