If you’ve ever donated blood or gone for a blood test then you might have been asked about your blood type. It was once thought that all blood types were the same and that we could give anyone someone else’s blood without concern. However, now we know there are many different blood types that affect our susceptibility to diseases and our general health.

How do we get different blood types?

We inherit our blood type from our parents. In total, there are eight main blood types. These are separated into two categories: the ABO system (which includes blood types A, B, AB, or O) and the Rhesus factor (this can be positive or negative).

Your blood type is determined by combining these two systems. For example, the most common blood type in Australia is O+ with over 40% of the population belonging to this group. In contrast, the least common blood group is AB- with only 1% of Australians having this type running through their veins.

Why are blood types important?

Knowing your blood type is key if you ever need a blood transfusion. The best possible match for a transfusion is someone that’s the same blood type as you. However, this isn’t always possible in emergency situations.

Some blood type are universal donors, this means they can be given to anyone. O- red blood cells are often used for this reason. AB plasma (whether it’s positive or negative can also be given to anyone. Anyone with a universal type is encouraged to donate blood.


There are many reasons you may need a blood transfusion, here are some of the most common:

  • Cancer
  • Operations
  • Anaemia
  • Iron Deficiency
  • Bleeding Disorders
  • Pregnancy and child birth

What do our blood types effect?

In the late 1990s and early 2000s people believed blood types effected what we should eat and should not eat. However, many people pointed out this diet wasn’t supported by science. Some Asian nations use blood types to define your personality or find you a life partner, but ultimately blood types have only been proven to alter our susceptibility to diseases.

Recent studies are starting to show that your blood group may make you resistant or prone to certain diseases. In these findings, it was noted that O blood groups were less likely to develop coronary heart disease, while AB and B blood groups have a higher risk of developing ovarian cancer.

These experiments also found:

  • O blood groups are less likely to have cancer, but more susceptible to norovirus.
  • A higher risk of renal cancer was found in non-O group women.
  • Women with O group blood are twice as likely to have a lower egg count and poorer egg quality, whereas blood group A women had the best egg quality and fertility.