We all understand that Blood groups are a necessary aspect when it comes to human biology. It is necessary for understanding our genetics and even medical compatibility in some scenarios. Back in the past, Karl Landsteiner categorized blood groups on the basis of the presence or absence of certain antigens in the red blood cells. The ABO system suggests that there are four major groups- A, B, AB, and O. Then, comes the Rh factor as well. It further divides the blood groups in Rh-positive and Rh-negative categories.

Well, if you wish to know more about this in detail, keep reading this blog. 

More About the Blood Groups

Let’s first find out the major types of blood groups. 

In layman’s terms, a blood type is a sort of ‘classification system’. Yes, that’s true! Your healthcare provider can only determine if one’s blood is compatible with someone else’s or not with the help of blood groups. 

Now, there are four main blood types: A, B, AB and O. And, as said above, Rh factors matter as well. This means there are a total of eight common blood types:

  • A positive (A+)
  • A negative (A-)
  • B positive (B+)
  • B negative (B-)
  • AB positive (AB+)
  • AB negative (AB-)
  • O positive (O+)
  • O negative (O-)

How Are Blood Types Determined?

Till now, we understood that there are different types of blood groups. But how are they actually determined? Let’s read below. 

Blood types are determined by the presence or absence of certain antigens on the surface of red blood cells. These antigens are molecules that trigger the body’s immune response. 

1. ABO System

This system classifies blood into four main types: A, B, AB, and O. These types are determined by the presence or absence of antigens called A and B on the surface of red blood cells. Type A blood has A antigens, type B blood has B antigens, type AB blood has both A and B antigens, and type O blood has neither A nor B antigens.

2. Rh System

The Rh system determines whether an individual’s blood is Rh-positive or Rh-negative. The Rh antigen is either present (+) or absent (-) on the surface of red blood cells. If a person’s blood has the Rh antigen, they are Rh-positive. If the Rh antigen is absent, they are Rh-negative.

Blood type inheritance follows specific patterns. For example, if both parents are type A, their child could be type A or type O, depending on whether they inherit an A antigen from one or both parents. 

Which Is the Rarest Blood Group Types? 

The rarest blood types are AB negative and B negative. This rarity is because they have both the A and B antigens, along with the absence of the Rh antigen (negative).

  • AB Negative: This blood type is rare because it requires inheriting both A and B antigens from parents who may not have the same blood type. Also, the absence of the Rh antigen further reduces its occurrence.
  • B Negative: Similar to AB negative, this blood type is rare due to the combination of B antigens and the absence of the Rh antigen. It’s less common because it requires inheriting the B antigen from one parent and the absence of the Rh antigen from both parents.

Because these blood types are scarce, finding compatible donors can be challenging, especially in emergency situations. 

Which Is the Most Common Blood Type? 

The most common blood type is O positive. This blood type is prevalent because it lacks both A and B antigens, making it compatible with transfusions for a wide range of recipients. Additionally, the Rh antigen is present, further contributing to its frequency. O positive blood can be transfused to individuals with A, B, AB, or O blood types, making it in high demand for emergency situations and everyday medical procedures. 

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Overall, the blood group chart varied thanks to multiple factors. Yet, you can get your blood group test done in your nearby hospital to find out your blood type. Hope this article helps.