BY- JAYA CHOUDHARY
Blood types have been around for at least 20 million years, according to scientists, but physicians have only known about them for the last 116 years. Thousands of people died before 1900 as a result of receiving the wrong blood. But what makes one blood group inappropriate for one person but acceptable for another?
Proteins called ‘antigens’ are one of the reasons. Your blood group is determined by the surface of red blood cells. Type A blood, for example, contains antigens of type A, while type B blood contains antigens of type B. When blood types A and B are mixed, the body goes into a full-fledged battle. Antibodies in your blood plasma guard the body for anything foreign, including antigens that aren’t compatible with your blood group. When the incorrect antigens are injected, antibodies attack by binding to them, causing the blood to clump.
These clumps clog blood vessels, disrupting circulation and potentially resulting in death. It only takes a few milliliters of the incorrect blood to trigger a severe reaction, so knowing your blood group is crucial. There are 35 different blood group systems in the world, but yours is most likely one of the two most common. The ABO and Rh groups are the two types of blood groups. These classes comprise the eight blood groups that account for more than 90% of the world’s population.
About 65 percent of all human blood types are O+ and A+. However, blood types may differ from one place to other. Type O blood, for example, is much more prevalent in the Western hemisphere, while both types A and B are much more prevalent in the Eastern hemisphere. Your chances of becoming B positive in India are four times higher than in the United States. AB- blood type is a rare blood group with a worldwide prevalence of less than 2%.
Scientists are also baffled as to why there are so many different blood types and where they originate from. We know that blood types are not unique to humans. Dogs, cats, horses, and monkeys, to name a few, all have them, but antigens in animals are normally different from those in humans. There is also a growing body of research that blood types play a role in our defense or lack thereof against certain diseases. People with blood type A, for example, are more likely to develop pancreatic cancer, leukemia, smallpox, and serious malaria.
While people with blood group O are less likely to get serious malaria, but they are more susceptible to ulcers and Achilles tendon ruptures. So, the next time you donate blood, take a few moments to consider how strange a business it is when that blood eventually enters another human being.