Guide To Understanding The Different Blood Types

Blood is made up of red blood cells, white blood cells, platelets, and plasma. Markers called antigens are found on the surface of red blood cells, and differences in these markers are used to classify the various types of blood. There are thirty-five different systems of blood group classification. Currently, blood is primarily categorized according to its ABO group and the presence or absence of Rh factor. Types, A, AB, O, and B make up the ABO group, and each of these can be either positive or negative for Rh factor. For example, an individual may have A positive blood or A negative blood, or they might have O positive or O negative blood.