Question

What exactly do the positive and negative mean after the blood types of A, B, AB or O?

Answer 1

An individual either has or does not have the Rh factor ( Rhesus antigen D ) on the surface of their RBC's ( red blood cells ) . This status is indicated by positive or negative suffix to the ABO blood type.

Explanation:

Rh phenotypes are identified by identifying the presence or absence of Rh surface antigens.

Besides its role in blood transfusion the Rh blood group system is used to determine the risk of hemolytic diseases of the newborns.

People with Rh negative blood will show serious transfusion reaction if they receive Rh positive blood.

Immunisation against Rh can generally occur through blood transfusions or placental exposure during pregnancy in women.