A 68-year-old male is admitted to the hospital for emphysema. He is hypoxic and his labs reveal low oxygen levels. His hematocrit is 65%. The physician has told him that he has a type of polycythemia in which he has an increased number of erythrocytes circulating in his blood stream. The client tells the nurse that he does not understand what that means. How would the nurse explain this in terms the client would understand?