If you lose blood because of an injury or surgical procedure, or if your body has trouble making blood, you may need a blood transfusion. This is a common procedure that adds blood from a donor to your own blood.
Not everyone's blood is exactly the same. Blood from one person may have small differences when compared to blood from another person. We use these differences to group blood into categories we call "types." There are eight common blood types.
A helpful guide to safely using IV antibiotics.