
While all blood does the same thing, namely transporting oxygen, removing waste products, fighting infections and regulating body temperature, it's clear that not all blood is actually the same.
Now, our blood type is determined by the blood groups of our parents and there are four 'types' of blood with every person either A, B, AB or O.
Each of these groups can then be further classified, as either 'positive (+)' or 'negative (-)' depending on the absence or presence of the Rh factor’s D antigen which is another marker - something known as the Rh system.
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So, you could possibly be one of eight common blood types which refers to whether or not your blood carries the marker with RhD positive being more common than being RhD negative.

What are the eight common blood types?
These include:
- A positive (A+).
- A negative (A-).
- B positive (B+).
- B negative (B-).
- AB positive (AB+).
- AB negative (AB-).
- O positive (O+).
- O negative (O-).

What do these blood types mean?
Now, as previously outlined, most people think of A, B, AB and O when they hear the phrase 'blood types'.
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Such letters classify blood types based on whether red blood cells have the A antigen or B antigen - something known as the ABO system.
So this means, for example, those who are Type A have red blood cells have the A antigen while Type B people have red blood cells have the B antigen.
Meanwhile, Type AB people have red blood cells have both A and B antigens while those who are Type O have red blood cells have neither A nor B antigens.
According to the NHS, the main difference between antigen A and B on red blood cells is that:
- Blood group A - has A antigens on the red blood cells with anti-B antibodies in the plasma
- Blood group B - has B antigens with anti-A antibodies in the plasma
- Blood group O - has no antigens, but both anti-A and anti-B antibodies in the plasma
- Blood group AB - has both A and B antigens, but no antibodies

Which blood group is linked to a lessened chance of developing cancer?
A study conducted in 2015 reportedly ruled that only one of the four blood groups had been linked to a lessened chance of developing certain strains of cancer.
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The research in question ruled that the Type O blood group has a lessened risk of such a diagnosis - though, it's vital to note that there is no significant correlation between blood groups and mortality rates in cancer cases.
Such was also the pattern in pancreatic cancer diagnoses - with Types A, B, and AB blood types having an increased risk.
Meanwhile, the O blood type has been linked with a reduced risk of various colorectal cancer.
Dr Sanjay Aggarwal - a general physician at Holistic Healthcare Centre in Delhi - recently emphasised, however: "It may be more accurate to say people with type O blood are at a lower risk for pancreatic cancer, given the work researchers are doing on bacterial infection."
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If you’ve been affected by any of these issues and want to speak to someone in confidence, contact Macmillan’s Cancer Support Line on 0808 808 00 00, 8am–8pm seven days a week.