In a patient with severe COPD, which hematologic change is commonly seen due to chronic hypoxemia?

• A. Anemia
• B. Polycythemia
• C. Neutropenia
• D. Thrombocytopenia

Answer: (B)

Chronic hypoxemia from severe COPD stimulates the kidneys to release more erythropoietin, which drives the bone marrow to produce more red blood cells. This results in secondary polycythemia, increasing both hemoglobin and hematocrit as the body attempts to improve oxygen delivery despite low arterial oxygen. The trade-off is thicker blood, which raises viscosity and the risk of thrombosis and cardiovascular strain.

Anemia would lower red cell mass, not increase it, so it’s not the typical response to chronic hypoxemia. Neutropenia or thrombocytopenia aren’t direct consequences of sustained low oxygen levels and don’t reflect the compensatory rise in red blood cells seen in COPD.