rhesus means
Rh is short for Rhesus factor. Rhesus factor is a type of antigen present on the surface of red blood cells. If you have have this particular antigen, you are Rh positive. If you donât, youâre Rh negative.The Rh factor is important in determining blood type for transfusions.Normally Your immune system protects against potentially harmful substances (antigens).f you have have this particular antigen, you are Rh positive. If you donât, youâre Rh negative. The Rh factor is important in determining blood type for transfusions. Normally Your immune system protects against potentially harmful substances (antigens).