What can a high MCH blood test result indicate?

Q. My CBC shows an abnormal MCH reading of 31.3. What is MCH, and what does this mean for my health?

A. Your slightly high MCH reading likely has no bearing on your health, assuming the rest of your CBC results are normal.

The laboratory report of a complete blood count (CBC) includes information about red blood cells, white blood cells, and platelets.

The details about red blood cells are reported as follows:

• Hematocrit (Hct). This is the percentage of your blood sample that are red blood cells. (The rest is plasma).
• Hemoglobin (Hgb). This is the amount of the oxygen-carrying protein in 100 milliliters of blood.
• Red blood cell count (RBC count). This is the number of red blood cells in one milliliter of blood.
• Mean corpuscular volume (MCV). This is the average size of your red blood cells.
• Mean corpuscular hemoglobin (MCH). This is the average amount of hemoglobin in each red blood cell.
• Mean corpuscular hemoglobin concentration (MCHC). This is the average amount of hemoglobin relative to the average size of red blood cells.

Hematocrit and hemoglobin are the two most important values. For an adult woman, a hematocrit less than 36 or a hemoglobin level less than 12 indicates anemia. For a man, the numbers are 40 and 13.5.

The other values related to red blood cells are most helpful when a person is anemic. For example, a normal MCH is 27 to 31. However, a number slightly higher than 31 is perfectly fine if your hematocrit and hemoglobin are normal.

MCH is used primarily to help determine if someone has iron deficiency anemia. In that case, the MCH tends to be low, not high like yours.

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