Why would someone need a blood transfusion?

Question

Why would someone need a blood transfusion?

Answer 1

Ok... This question really suprise me! When people lose blood (in accident, or they have hemofilia (unpossibility to stop bleeding), ... etc.) they have to receive blood by transfution, but it has to be the same blood group!

Answer 2

For a couple reasons. If someone lost enough blood in a traumatic accident (shooting, stabbing, broken bones) they would need more blood. And some medical conditions require blood transfusions. If someone has kidney failure and cannot filter their blood they go an dialysis, form of transfusion.

Answer 3

Blood transfusions are needed when someone loses a lot of blood and/or does not have the ability to produce more at a sufficient rate.  Think injury with blood loss or cancer with bad bone marrow.  The goal is to replace their own blood with some that is very similar until their body can recover, allowing the body to deliver and use oxygen normally.