A positive blood type, which is a comprehensive expression of a person’s blood type, because there are dozens of human blood types, there are two widely used in clinical practice, one is the ABO blood group system and the other is the Rh blood group system. the ABO blood group system divides human blood types into four categories, namely A blood type, B blood type, AB blood type and O blood type. the Rh blood group system divides Rh blood groups are divided into two categories, Rh-positive if they contain D antigen and Rh-negative if they do not contain D antigen. At the same time, D antigen is a very strong antigen that stimulates the body to produce antibodies, which results in an antigen-antibody reaction. Therefore, A-positive blood means that a person’s blood type is A-positive in the ABO blood group system and Rh-positive in the Rh blood group system.