MCH - Kresser Institute Membership Site

Marker Name: MCH

REFERENCE RANGES FOR MCH:

Laboratory reference range: 26.6–33 pg/cell

Functional reference range: 27.7–32 pg/cell

DESCRIPTION:

Mean corpuscular hemoglobin (MCH) is the mass of hemoglobin in the average red blood cell,¹ though in practice the test provides limited information about hemoglobin within red blood cells.

MCH is not measured directly; it is calculated from hemoglobin concentration and red blood cell count.

MCH formula

MCH is an indication of average values and may not precisely account for variability within mixed populations of red blood cells.² For example, iron-deficiency anemia may result in decreased mean corpuscular volume (MCV) and MCH, while megaloblastic anemia may result in increased MCV and MCH.

The laboratory value of MCH may be incorrectly high or low when hemoglobin concentration and red blood cell count cannot be accurately measured. For example, people with exceptionally high levels of circulating lipids will have a high degree of plasma turbidity.³ This plasma turbidity will artificially increase measured hemoglobin and will consequently deliver a falsely elevated MCH. Thus, MCH can be useful for suggesting a possible spurious hemoglobin lab result.

In the context of anemia, a high MCH signifies hyperchromic anemia.⁴ Conversely, a low MCH signifies hypochromic anemia.⁴ These diagnoses can only be definitively made, however, in conjunction with mean corpuscular volume. This is because red blood cell volume affects the concentration of hemoglobin within each cell, which is reported as MCHC. Thus, MCH can vary in parallel to MCV under physiological circumstances.^5,6

MCH is always measured as part of a complete blood count (CBC).⁷ MCH is of little clinical significance in isolation and must be considered in conjunction with hemoglobin, RBC count, MCV, and RDW.¹

PATHOLOGICAL/CONVENTIONAL RANGE INDICATIONS: High in:^5,7

Macrocytosis

Low in:^5,7

Iron deficiency
Thalassemia

FUNCTIONAL RANGE INDICATIONS:

High in:

Same as conventional indications

Low in:

Same as conventional indications

References: