Blood type (ABO)

Blood type, specifically the ABO system, classifies human blood into four main groups: A, B, AB, and O. This classification is based on the presence or absence of specific antigens (A and B) on the surface of red blood cells. Type A has A antigens, type B has B antigens, type AB has both, and type O has neither. Blood type is crucial for blood transfusions and organ transplants because mixing incompatible types can cause serious health issues. Understanding your blood type is important for medical emergencies and blood donation compatibility.