Which term refers to a decreased production of red blood cells?

The term specifically referring to a decreased production of red blood cells is primary anemia. Primary anemia often arises from intrinsic factors affecting the bone marrow or the erythropoietic process directly and can be due to conditions such as aplastic anemia or certain types of nutritional deficiencies.

In this context, anemia in general refers to a condition characterized by a deficiency in red blood cells or hemoglobin, which can result from various etiologies including decreased production, increased destruction, or blood loss. However, since the question specifically seeks to identify terms related to decreased production, primary anemia fits best as it focuses on the root cause of the reduced erythropoiesis.

Leukemia, on the other hand, is a malignancy related to white blood cells and can affect red blood cell production indirectly by crowding out the normal hematopoietic cells in the marrow, but it does not specifically denote reduced production of red blood cells as its primary context. Pneumoconiosis is a type of lung disease resulting from inhalation of dust, and while it may affect overall health and oxygen transport, it does not directly pertain to red blood cell production either.