<prompt> Cyanosis is not seen in severe anemia because?Anemic hemoglobin has greater oxygen carrying capacity per unit gram of hemoglobinCritical concentration of reduced hemoglobin is requiredIncreased RBC number counter-balances the oxygen shoageBlood flow through the skin is decreased in anemia  <response>: Cyanosis is not seen in severe anemia because a critical concentration of reduced hemoglobin is required. Cyanosis Bluish discoloration of skin mucous membranes due to an increased quantity of reduced Hb i.e., deoxy Hb or Hb derivatives e.g., met Hb or sulfhemoglobin in the small blood vessels. Cyanosis becomes apparent when the concentration of reduced hemoglobin in capillary blood 4 gdL. Absolute, rather than the relative, quantity of reduced Hb that is impoant in producing cyanosis. In a patient with severe anemia, the relative quantity of reduced Hb in the venous blood may be very large, but the absolute quantity of reduced Hb is still small. Therefore, patients with severe anemia even marked aerial desaturation may not display cyanosis. 