All of us have blood. Though all blood looks the same and serves the same purpose, all blood is not similar. Your genes determine your blood group. The antibodies and antigens in your blood decide the blood group.  

Rhesus (Rh) factor 

Rhesus (Rh) factor is a deciding element for blood. This Rh factor is an inherited protein found on the surface of red blood cells. It is either from the mother or father.  

You are Rh-positive if your blood has this protein. You are Rh-negative if your blood lacks this protein. The majority of the people are Rh-positive. 

How significant is the Rh factor? 

You can be Rh-positive or Rh-negative. Your overall health is not affected by the presence and absence of the Rh factor.  

Pregnancy and Rh Incompatibility 

If you are pregnant, it is essential to know your Rh factor. If the mother is Rh-negative and the fetus is Rh-positive, it can cause complications. This condition is called Rh incompatibility. It can sometimes lead to difficult situations and result in the death of the fetus or the newborn. Rh Incompatibility can cause jaundice in a newborn. 

Human blood is divided into various groups or types

There are four major blood groups. It is determined by the presence or absence of two antigens –A and B on the surface of red blood cells and the presence and absence of the Rh factor.  

In short, there are eight common blood groups.   

1. Group A+: This blood has A antigen on red blood cells (and B antibody in the plasma) 
2. Group A-: Rh factor is absent.  
3. Group B+: This blood has B antigen on red blood cells (and A antibody in the plasma) 
4. Group B-: Rh factor is absent.  
5. Group AB+: This blood has both A and B antigens on red blood cells (but neither A nor B antibodies in the plasma)   
6. Group AB-: Rh factor is absent.  
7. Group O+: This blood has neither A nor B antigens on red blood cells (but A and B antibodies are in plasma)  
8. Group O-: Rh factor is absent.  

In addition to these, there are more than 30 different blood group systems related to different types of antigens.  

Universal Donor and Recipient  

• Group O- (Type O negative) is the universal red cell donor. Anyone can receive type O- (packed red blood cells)  
• Group AB + is the universal recipient for packed red cell transformation.