Final answer:
An increased amount of polychromatic red blood cells on a blood smear is most likely due to anemia, where immature red blood cells are elevated to compensate for a deficiency in oxygen transport capacity.
Step-by-step explanation:
The most likely cause for an increased amount of polychromatic red blood cells on a blood smear is that the patient is anemic. Polychromatic red blood cells are immature erythrocytes, also known as reticulocytes. These cells are typically elevated in response to anemia, as the body attempts to compensate for the decreased oxygen-carrying capacity by producing and releasing more immature red blood cells into the bloodstream.
An increased reticulocyte count can be observed during various anemia situations such as blood loss, faulty or decreased RBC production, or excessive destruction of RBCs. It's a reflection of the body's response to the imbalance and needs to maintain adequate oxygen delivery to tissues. Anemia leads to symptoms such as fatigue, lethargy, and an increased risk for infection due to reduced numbers of mature RBCs or hemoglobin, which implies a lower level of oxygen being delivered to body tissues. An effective treatment plan will be directed at the underlying cause of the anemia to restore the balance of red blood cell production and destruction.