Blood test

Low MCH level in the blood

Blood test
Low MCH level in the blood

What is a low MCH called?

  • Hypochromia

What is the normal MCH level in the blood?

If you need to know which are the MCH reference ranges or you require more information about the role of MCH in the blood you can visit: Normal MCH level in the blood

What does a low MCH in a blood test mean?

A low MCH (Mean Corpuscular Volume) in a blood test is called hypochromia. It means that RBCs have a small amount of hemoglobin and they have a paler red color.

The main cause of a low MCH is iron-deficiency anemia. It comes with anemia (a low hemoglobin value) and microcytosis (MVC below normal range).

MCH test is interesting because a low MCH may be the first sign of iron-deficiency anemia.

Hypochromia is also related to thalassemia (frequent in the case of beta thalassemia) and sideroblastic anemia. Besides, lead or copper poisoning is also a cause of hypochromia.

Hypochromia or a low MCH level in the blood means:

  • Mild hypochromia (25 - 27 pg in adults):

    A mild hypochromia may a consequence of an iron-deficiency anemia due to excessive bleeding (menstruation, ulcer, hemorrhoids, and esophageal varices). In mild hypochromia, hemoglobin values are usually between 10 and 12 g/dl.

  • Moderate hypochromia (22 - 25 pg in adults):

    A moderate hypochromia may be due to a marked iron-deficiency anemia where hemoglobin level is between 9 and 10 g/dl. It comes along with microcytosis (MCV < 80).

    A moderate hypochromia is also typical in the case of some types of thalassemia, such as alpha thalassemia or beta thalassemia minor.

  • Marked hypochromia (20 - 22 pg in adults):

    A marked hypochromia may be a sign of a severe iron-deficiency anemia where hemoglobin level is very low and there is an evident microcytosis (a low MCV).

    It is also characteristic of suffering from some type of beta thalassemia such as beta thalassemia intermedia with values between 16 and 24 pg (hemoglobin will be between 7 and 10 g/dl and MCV between 50 and 80 fl) or the hemoglobin H disease.

  • Severe hypochromia (< 20 pg in adults):

    A severe hypochromia may be due to a very severe iron-deficiency anemia with a very low hemoglobin level in the blood (below 5 g/dl).

    It may also occur in case of severe thalassemia such as beta thalassemia major with a MCH level between 12 and 20 pg and along with hemoglobin below 7 g/dl and MCV between 50 and 70 fl.

    The symptoms of anemia will be present such as fatigue, palpitations, fainting, etc. Immediate medical help is necessary to avoid heart problems.

Which factors can reduce the MCH?

There are some circumstances and drugs that may reduce your MCH:

  • Copper poisoning
  • Lead poisoning

Which diseases can reduce your MCH?

A lower than normal MCH may be due to:

  • Iron-deficiency anemia
  • Thalassemia
  • Sideroblastic anemia
  • Saturnism

What can I do to increase the MCH level in the blood?

The main reason for a low MCH is suffering from iron-deficiency anemia. For this reason, it is advisable to increase the intake of iron in the diet. The following foods are rich in iron:

  • Red meat: Beef or pork, mainly liver and kidney.
  • Legumes: Chickpeas, lentils.
  • Fish and seafood: Sardines, mussels and oysters.
  • Eggs.

If values keeps on high in future tests may be due to a thalassemia that requires further research.

Where can I find more information about MCH level in the blood?

You can visit our pages about:

Which values are considered a low MCH level in the blood?

The following values are considered to be above the normal range:

IMPORTANT: These levels are expressed in pg (picograms). They are an example of a healthy woman of about 45 years old with no known disease and not taking any medication. The ranges can be different depending on the laboratory or on your personal circumstances.

Mild hypochromia
26.9 pg26.8 pg26.7 pg26.6 pg26.5 pg26.4 pg26.3 pg26.2 pg
26.1 pg26 pg25.9 pg25.8 pg25.7 pg25.6 pg25.5 pg25.4 pg
25.3 pg25.2 pg25.1 pg25 pg    
Moderate hypochromia
24.9 pg24.8 pg24.7 pg24.6 pg24.5 pg24.4 pg24.3 pg24.2 pg
24.1 pg24 pg23.9 pg23.8 pg23.7 pg23.6 pg23.5 pg23.4 pg
23.3 pg23.2 pg23.1 pg23 pg22.9 pg22.8 pg22.7 pg22.6 pg
22.5 pg22.4 pg22.3 pg22.2 pg22.1 pg22 pg  
Marked hypochromia
21.9 pg21.8 pg21.7 pg21.6 pg21.5 pg21.4 pg21.3 pg21.2 pg
21.1 pg21 pg20.9 pg20.8 pg20.7 pg20.6 pg20.5 pg20.4 pg
20.3 pg20.2 pg20.1 pg20 pg    
Severe hypochromia
19.9 pg19.8 pg19.7 pg19.6 pg19.5 pg19.4 pg19.3 pg19.2 pg
19.1 pg19 pg18.9 pg18.8 pg18.7 pg18.6 pg18.5 pg18.4 pg
18.3 pg18.2 pg18.1 pg18 pg17.9 pg17.8 pg17.7 pg17.6 pg
17.5 pg17.4 pg17.3 pg17.2 pg17.1 pg17 pg16.9 pg16.8 pg
16.7 pg16.6 pg16.5 pg16.4 pg16.3 pg16.2 pg16.1 pg16 pg
15.9 pg15.8 pg15.7 pg15.6 pg15.5 pg15.4 pg15.3 pg15.2 pg
15.1 pg15 pg14.9 pg14.8 pg14.7 pg14.6 pg14.5 pg14.4 pg
14.3 pg14.2 pg14.1 pg14 pg13.9 pg13.8 pg13.7 pg13.6 pg
13.5 pg13.4 pg13.3 pg13.2 pg13.1 pg13 pg12.9 pg12.8 pg
12.7 pg12.6 pg12.5 pg12.4 pg12.3 pg12.2 pg12.1 pg12 pg
Last update: 07/01/2021


  • Concise Book of Medical Laboratory Technology: Methods and Interpretations. 2nd Edition. 2015. Ramnik Sood. ISBN: 978-93-5152-333-8. Pag. 217.
  • A Manual of Laboratory and Diagnostic Test. 9th edition. Frances Fischbach. Marshall B. Dunning III. 2014. Pag 100. ISBN-10: 1451190891.
  • Laboratory tests and diagnostic procedures with nursing diagnoses (8th ed), Jane Vincent Corbett, Angela Denise Banks, ISBN: 978-0-13-237332-6, Pag. 35.

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