A high hemoglobin level in the setting of lung disease or low oxygen tension indicates which form of polycythemia?

A high hemoglobin level in the setting of lung disease or low oxygen tension indicates which form of polycythemia?

• A. Polycythemia vera
• B. Secondary polycythemia (high EPO)
• C. Iron deficiency anemia
• D. Polycythemia without changes in EPO

Answer: (B)