MCH Blood Test Explained
Hemoglobin is the substance that is responsible for carrying, through the bloodstream, oxygen from the lungs to the different cells of the body. The mean corpuscular hemoglobin (MCH) value is the average amount of hemoglobin contained within a person’s red blood cells.
The value is related to two other values—MCV (mean corpuscular volume) and MCHC (mean corpuscular hemoglobin concentration).
The former measures the average size of red blood cells, while the latter calculates the amount of hemoglobin in a single red blood cell per unit volume.
MCH is different from MCHC because it does not take into account the volume or size of the red blood cell.
What is an MCH blood test?
The test is done to calculate the average amount of hemoglobin contained within a person’s red blood cells. The result usually mirrors MCV because bigger red blood cells contain more hemoglobin, while smaller ones tend to have less.
When the MCH level is abnormally high or low, it indicates a number of problems in the body.
The MCH blood test is part of the complete blood count (CBC) test that evaluates the composition of blood, including the hemoglobin. It is not measured directly but calculated based on the value of hemoglobin (Hgb) and the number of red blood cells (RBC) in the blood.
The Hgb is divided by the RBC, the quotient of which is the average amount of hemoglobin in each red blood cell. If the MCH falls between 26 and 33 pg (picograms) of hemoglobin for RBC, it is normal for adults. The numbers are different for young children.
The normal levels may also vary based on the machine used during the test.
Low MCH Levels
MCH levels with concentrations at or below 26 pg per cell are low.
This can be a result of different types of anemia, such as microcytic anemia, which can be due to nutritional deficiencies or malnutrition. In this case, the blood cells are too small and are incapable of taking in normal levels of hemoglobin.
Low MCH levels are also caused by:
- Low amounts of iron in the blood
- Due to Celiac disease
- Lack of key vitamins
If vitamin deficiency is suspected to be the cause of low MCH, further tests are done for confirmation because the condition can also lead to the opposite—high MCH.
Adding iron-rich foods to your diet and taking iron supplements can treat low MCH. In severe cases, however, blood transfusion is needed.
High MCH Levels
MCH levels over 34 pg are abnormally high and may be due to macrocytic anemia, a blood disorder where the body fails to produce the right amount of red blood cells. Instead, the red blood cells produced are larger than usual, which means each cell carries more hemoglobin than cells with a normal size.
Macrocytic anemia may be caused by a lack of vitamin B12 or folic acid in the body. The deficiency may be because your body is unable to absorb or process the needed vitamins.
High MCH levels are also caused by:
- Other forms of anemia
- Chemotherapy
- Some forms of leukemia
- Certain infections
- Thyroid dysfunction
- Overuse of estrogen-containing medications
Hereditary spherocytosis can also lead to High MCH, what with it causing a shortage of red blood cells.
Adding foods rich in folate and vitamin B12 to your diet can treat high MCH. Taking supplements is another option. However, in cases where a body has difficulty processing or absorbing B12 and folate, B12 injections will be prescribed.
What is a CBC Test?
A CBC (Complete Blood Count) blood test is a common blood test that is used to measure a variety of components of the blood, such as the red blood cell count, the white blood cell count, hemoglobin, hematocrit, and platelet count. It can be used to diagnose a variety of conditions, such as anemia, infections, and various blood disorders. The test is usually done in a laboratory, and results are usually available within 1-2 days.
