Which blood type is considered the universal donor?

The blood type recognized as the universal donor is O negative. This is due to the absence of A and B antigens on the surface of red blood cells in individuals with this blood type. When O negative blood is transfused into patients of various blood types, it significantly minimizes the risk of an immune response, as there are no antigens present that could trigger a reaction in recipients who may have different blood types.

O negative blood can be safely given to any patient in emergencies when blood type matching is not possible, making it especially valuable in critical care situations. In contrast, other blood types carry specific antigens that can lead to complications during transfusions if the recipient’s immune system recognizes those antigens as foreign. Therefore, O negative serves a crucial role in transfusion medicine and is essential for ensuring patient safety during unexpected medical emergencies.