Blood Group Doubt

Question

O blood group is a universal donar then why it is not given to all?

Answer 1

It can be, but blood is not in infinite supply-- it depends on who has donated. If someone is able to use a different blood type then type O, that will be used first since O can be used for everyone.

 

For example, if a person of type A needs blood, they can only receive type A or type O - if type A is available then they will use it, if not then they can use the type O instead. However, someone who is blood type B would not be able to use the type A blood (only B or O).