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Blood Compatibility Chart: Why is Compatibility Important?

Blood Compatibility Chart: Why is Compatibility Important?

You’re probably familiar, or at least have heard of blood types or blood compatibility. Why do people have different blood types, and why is it so important to be given the right one? Read on to learn the answers to these questions, the blood compatibility chart, and more.

Why do we have different blood types?

Before we get to blood compatibility and the blood compatibility chart, we first need to understand why we have different blood types1 in the first place.

One factor that determines blood type is the antigens in a person’s blood. These are chemicals found in the blood that can trigger an immune response. These antigens are known as either antigen A or antigen B.

Type A blood means that antigen A can be found in the red blood cells, and antigen B is in the plasma of the blood. Type B, on the other hand, means that antigen B is in the red blood cells, and antigen A is in the plasma.

People can also have type AB blood, which means that their red blood cells both contain antigen A and antigen B, and none are present in plasma. The inverse of this is type O blood, wherein there are no antigens in the red blood cells, but the plasma has both antigen A and antigen B.

There is also a type of protein, known as the Rh factor, which is another factor when it comes to our blood types. The presence of the Rh factor is symbolized by a (+) symbol, and the absence of it by a (-) symbol.

When we combine the antigens and the Rh factor, we get a total of 8 common blood types. These are are: A+, A-, B+, B-, O+, O-, AB+, AB-.

People with blood type O are considered as universal red blood cell donors, while those with blood type AB are universal plasma donors. These blood types are highly in demand because of their compatibility with the other blood types. You can refer to the blood compatibility chart to see which are types are more compatible with other blood types.

Why is blood compatibility important?

If you’ve ever come across the blood compatibility chart, you’ve probably noticed how other blood types are more compatible.

Blood compatibility is very important because of the antigens found in the blood. If the antigens are incompatible, then the immune system will start to attack the blood cells that are foreign to the body. To the immune system, these cells are invaders, even if they pose no threat to the body.

When this happens, the blood cells can start to clump, and this leads to a life-threatening situation2.

In the case of Rh positive and Rh negative blood, this usually causes no problem if a person is given a different type. However, it can be a significant problem during pregnancy.

This is because if there is an incompatibility in the Rh factor of a mother and her baby, it could trigger a reaction. This reaction can cause anemia or brain damage, or it can even be fatal to the unborn baby. Thankfully, this problem can be mitigated through the use of medication.

For these reasons, it’s always important to know your blood type. Inform your friends and loved ones about it just in case.

How can you know your blood type?

Knowing your blood type is as simple as going to a clinic to undergo blood typing, or ABO typing. This is a process wherein a sample of your blood will be taken and tested3.

During the test, a medical practitioner will be adding different antigens to your blood sample. Depending on the results, such as if the blood clumps, this would show what type of blood a person has.

The test for the Rh factor is also similar. But the difference is it checks for the presence of the protein in the blood.

It’s a good idea to get you and your family’s blood type tested. This is useful information to have in case of emergencies.

The blood compatibility chart

The blood compatibility chart is a handy guide that shows which blood types can donate.

Here is a quick rundown of the chart4:

blood compatibility chart

For any questions or concerns about your blood type, consult your doctor as this information is important to know in case of future medical cases.

Learn more about Medical Procedures and Surgeries here.

Hello Health Group does not provide medical advice, diagnosis or treatment.

  1. Blood Types Explained – A, B, AB and O | Red Cross Blood Services, https://www.redcrossblood.org/donate-blood/blood-types.html, Accessed May 20, 2021
  2. Blood Types – A, B, AB and O Explained, https://www.pennmedicine.org/updates/blogs/health-and-wellness/2019/april/blood-types, Accessed May 20, 2021
  3. Blood typing: MedlinePlus Medical Encyclopedia, https://medlineplus.gov/ency/article/003345.htm, Accessed May 20, 2021
  4. Blood Safety and Matching – Hematology.org, https://www.hematology.org/education/patients/blood-basics/blood-safety-and-matching, Accessed May 20, 2021
  5. Blood Transfusion : Blood Groups and Compatibilities, https://www.rch.org.au/bloodtrans/about_blood_products/Blood_Groups_and_Compatibilities/, Accessed May 20, 2021
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Written by Jan Alwyn Batara Updated Jun 08, 2021
Fact Checked by Hello Doctor Medical Panel