Blood group systems

Blood group systems categorize blood based on specific markers called antigens on the surface of red blood cells. The most well-known system is the ABO group, which includes blood types A, B, AB, and O, determined by the presence or absence of A and B antigens. Another important system is the Rh factor, which indicates whether blood has a particular protein, positive or negative. These groups are crucial for safe blood transfusions, organ transplants, and pregnancy, as incompatible combinations can cause immune reactions. Overall, blood group systems help ensure compatibility and prevent adverse reactions in medical procedures.