Another example of a target cell (or codocyte) is seen in the center of this slide. Notice that the hemoglobin in the center of this cell is lighter in appearance than in the previous slide. Target cells appear in conditions that cause the surface of the red cell to increase disproportionately to its volume. This may result from a decrease in hemoglobin, as in iron deficiency anemia, or an increase in cell membrane.
Target cells have excess membrane cholesterol and phospholipid and decreased cellular hemoglobin. Examples of other conditions in which target cells may be present include thalassemias, hemoglobin C disease, post splenectomy, and obstructive jaundice.