Increased RBC number per unit volume is called

Increased RBC number per unit volume is called

• A. Thrombocytosis
• B. Anemia
• C. Reticulocytosis
• D. Polycythemia

Answer: (D)

When RBC mass or concentration in the blood increases, the term used is polycythemia. This reflects a true rise in red cell mass (absolute polycythemia) or a higher concentration of red cells due to reduced plasma volume (relative polycythemia). It can arise from primary processes that boost red cell production, such as polycythemia vera, or from secondary causes like chronic hypoxia that drive more erythropoietin release. The other options describe different things: thrombocytosis means too many platelets; anemia means low red cell mass; reticulocytosis means more immature red cells being released from the marrow, often in response to loss or destruction of red cells but not a general increase in mature red cells per volume.

When RBC mass or concentration in the blood increases, the term used is polycythemia. This reflects a true rise in red cell mass (absolute polycythemia) or a higher concentration of red cells due to reduced plasma volume (relative polycythemia). It can arise from primary processes that boost red cell production, such as polycythemia vera, or from secondary causes like chronic hypoxia that drive more erythropoietin release. The other options describe different things: thrombocytosis means too many platelets; anemia means low red cell mass; reticulocytosis means more immature red cells being released from the marrow, often in response to loss or destruction of red cells but not a general increase in mature red cells per volume.