A finite life span is a distinct characteristic of red cells. Hence, a logical, time-honored classification of anemias comprises three groups: decreased production of red cells, increased destruction of red cells, and acute blood loss. Red cell destruction and acute loss, both associated with increased reticulocyte production, are covered in this chapter. Red cell production defects are discussed in Chaps. 98, 99, and 100. Physical loss of red cells from the bloodstream—which in most cases also means physical loss from the body—is fundamentally different from destruction of red cells within the body. .
