Why is the Mentzer index more than 13?

If the Mentzer index is more than 13, it suggests that the patient may have iron deficiency anemia rather than thalassemia.

• Iron deficiency anemia is a condition that occurs when there is a lack of iron in the body, which is necessary for the production of hemoglobin.
• Without enough hemoglobin, red blood cells cannot carry enough oxygen to the body's tissues, resulting in anemia.
• In iron deficiency anemia, the mean corpuscular volume (MCV) is usually low, and the red blood cell count (RBC) is also low.
• However, in thalassemia, which is an inherited blood disorder that affects the production of hemoglobin, the MCV is usually low, but the RBC count is high or normal.
• Dividing a low MCV by a high or normal RBC count results in a Mentzer index value that is less than 13.
• Therefore, a Mentzer index value of more than 13 may indicate iron deficiency anemia rather than thalassemia.

However, it is important to interpret the Mentzer index in conjunction with other laboratory and clinical findings to confirm the diagnosis.