Question

My doctor told me I have blood-type h-h. What does this mean?

Answer 1

The presence of a hereditary antigenic material on the surface of RBCs is used to classify blood groups. Karl Landsteiner first found it in 1901. He discovered that when various blood types were combined, the lack of molecules on RBCs caused some blood types' plasma to form clusters. He developed the Landsteiner Rule as a result of his observations. He separated the blood types into four categories: A, B, AB, and O. Furthermore, under normal circumstances, if an antigen is present in an individual's RBC, the matching antibody will not be present in their plasma.

Complete answer:
The h-h blood type is the rarest blood type in the world and is often recognized as the Bombay blood group.
This very unusual phenotype is found in around 0.0004% (about 4 people per million) of the human population, however in some areas, such as Mumbai (formerly Bombay), it can be found in as many as 0.01 percent (one person per 10,000) of the population, thus the term Bombay phenotype.
The red blood cells of the hh phenotype have a distorted form of the fundamental ABO antigen H or substance H, which may seem to be O type in normal blood group analysis. This indicates that transfer of ordinary O type blood into a hh person's body will cause coagulation.

Note:
The blood group system is important because it facilitates safe blood transfer. To put it another way, if a blood type other than ours is injected into our bodies, our immune systems will recognize it as a foreign particle. As a result, a transfusion response will occur, which is typically deadly. This is why it is suggested that blood types be tested prior to transfusion.