Which condition involves excessive red blood cells?

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

Answer: (B)

Polycythemia is the condition characterized by an abnormal increase in red blood cell mass. It shows up as elevated hematocrit and hemoglobin, confirming there are more red blood cells than normal. The extra cells make the blood thicker, which can raise the risk of clotting and put more strain on the heart. The other options describe low levels of specific blood components: thrombocytopenia means too few platelets, leukopenia means too few white blood cells, and anemia means not enough red blood cells or hemoglobin. Since the question asks which condition involves an excess of red blood cells, polycythemia is the correct choice.