EHS Blood Type

Blood Types

What is your blood type?


RH factor
This was a great discovery by K. Landsteiner and A. S. Wienerin in 1940 while studying Rhesus monkeys, a protein substance was identified on the red blood cells. This antigen was also present in the red blood cells blood of 85% of the humans tested. Other people, however, do not have the protein. The presence of the protein, or lack of it, is referred to as the Rh (for Rhesus) factor.

Blood that contained the Rh factor was called Rh positive and blood without the protein was called Rh negative.

RH negative is the recessive trait so it is possible you could carry the trait and yet have RH positive blood type. For example; A -/- mother (RH negative) and a +/+ father (RH positive) would have children with RH positive blood type but the children would be +/-. If and mother and a father had RH positive blood but with the +/- traits they could still have a -/- baby (Rh negative). For this reason we have added a question asking if your parent has RH negative blood even if you are RH positive (see the punnet square below). Just select unsure if you do not know this.





ABO system
An Austrian scientist called Karl Landsteiner found the three blood types A, B and O in 1900, while the type AB was discovered later in 1902. Identified by the different antigens, A-antigen, B-antigen, A&B-antigens present on the surface of the red blood cells. The O type had neither A or B Antigens. The ABO system and the RH factor breaks the blood groups into 8 different blood types:

AB+ A+ B+ O+ O- B- A- AB-


By grouping blood into this system human-blood transfusions became safer. Mixing incompatible blood types can have fatal consequences.

Identifying the Rh factor enables RH– women to have RH+ children without producing the antibodies that attack their unborn child because of the Rho-GAM (or Anti-D in NZ) injection, this was not discovered until the mid 1900’s which was not that long ago.

Food, allergies, bacteria and immunity issues can be specific to each blood group, there is still so much to find out and so much we don’t know that could significantly improve individual’s quality of life.

Quick tip: If you are unsure of your blood type, go give blood at your local blood bank, you will find out for free and be doing something good!

Interesting blood related information:

Did you know your O type blood helps you fight malaria?


Did you know two parents with O type blood could have a B type baby?