Blood transfusion question.

Why it is necessary to know blood types before a transfusion?

Because blood types can't mix.

If you try to give someone with B+ blood and A+ transfusion, it could have disastrous results.

Yeah, blood types cnt mix cuzz that could kill you which wouldn't be very good.

If incompatible blood is given in a transfusion, the donor cells are treated as if they were foreign invaders, and the patient's immune system attacks them accordingly. Not only is the blood transfusion rendered useless, but a potentially massive activation of the immune system and clotting system can cause shock, kidney failure, circulatory collapse, and death.

You body will reject the blood, and you wbc will attack the other cell, because the are different.

definitly!!! the transfution would be completly useless if you got the wrong blood type there are quite a few different types of blood..