Another great question, this one comes to us from Blake on Twitter!
I’ll step in to answer this one!
Your blood type is very important. It is basically a way to know what types of proteins are on your red blood cells. For example, if a person has type AB blood, this means their red blood cells are lined with type A and B proteins. Type A just has A proteins, type B has B proteins. Type O has neither. And while this is all well and good, the question still remains as to why that matters.
The most outstanding reason for why your blood type is important would be, for example, if you were in a situation where you needed a blood transfusion, whether that is due to an accident or perhaps an illness. You see, there are only certain blood types that can work together. If your body were to receive the wrong type of blood, it would see the new red blood cells as foreign pathogens (you know, the bad guys) and attack them like they would a germ. When this happens, it is called a hemolytic transfusion reaction, and on top of more serious effects, the body will have a lower blood pressure, fever, and possibly jaundice (yellowing of the skin) due to the liver processing the leftover hemoglobin in the blood stream.
People with type AB+ blood are known as universal receivers since they can accept all blood types. Alternatively, those with type O- blood are known as universal donors because their blood type can be combined with any other. This is because the red blood cells in type O blood have neither A nor B proteins and therefore will not be picked up as a pathogen by the immune system of the recipient. This is why people with type O blood are always in high demand as blood donors–if you qualify, please don’t hesitate to seek out your nearest Red Cross Blood Donation drive!
This, among other complications that can arise from an error with combining blood types, is why your doctor will take special care in knowing your blood type, and why you and your family should know it and have a blood type card.