- In iron deficiency anemia, there is a deficiency of iron which is essential for hemoglobin synthesis.
- This leads to the production of smaller red blood cells (microcytic) with reduced hemoglobin content (hypochromic).
- Consequently, red blood cells show a characteristic microcytic, hypochromic appearance on the peripheral smear.
- This morphological change reflects impaired hemoglobinization, a hallmark of iron deficiency anemia.
- Normocytic, normochromic cells are typical of early or mild anemia, while macrocytic cells are seen in vitamin B12/folate deficiency.
- Spherocytes are associated with hemolytic anemias, not iron deficiency.

Reference: Davidson’s Principles and Practice of Medicine, 23rd Edition, Chapter: Anaemia, Page 620.