MCH Blood Test

What is MCH in Blood Test?

MCH in blood test is usually a part of Complete Blood Count (CBC) test. The full form of MCH is “Mean Corpuscular Hemoglobin”. Hemoglobin is a protein in Red Blood Cells (RBC) that helps to carry oxygen and reach this oxygen into different parts of our body. So, through this MCH blood test, average amount of hemoglobin present in a single red blood cell is measured.

MCH Blood Test is done with MCV Blood Test and MCHC Blood Test. Your doctor can correlate all of these blood test results to diagnose the condition that you are suffering from. MCV, MCH, MCHC blood tests all together also known as Red Blood Cell Indices.

MCH Blood Test result tends to be similar like MCV Blood Test result. In high MCV there is increased size of Red Blood Cells, so generally contain more hemoglobin. As a result, MCH Blood test high level appears. Similarly, in low MCV there is smaller red blood cells that contain less amount of hemoglobin. So MCH becomes low.

MCH Blood Test Purpose

MCH blood test is usually done as routine blood test just like MCV and MCHC blood tests to assess anemia. Anemia is the medical condition where there is deficiency of hemoglobin in the blood due to either too few red blood cells (RBC), or too little hemoglobin in the body.

So, the MCH value determines the average amount of hemoglobin in a single red blood cell. When amount of hemoglobin is low, then oxygen carrying capacity of blood is low. As a result, deficiency of oxygen in different parts of your body will be prominent. So you will feel Fatigue, tiredness, loss of stamina, breathlessness, lightheadedness, etc. So the purpose of MCH Blood Tests are

  1. To determine the medical condition one is suffering from
  2. To predict the severity of an existing medical condition
  3. To diagnose the probable cause of the medical condition
  4. To evaluate the response of any ongoing treatment. Many times regular drugs that one takes for different health issues (like diabetes, cancer, etc.) causes high MCH level. So in that cases changing the drug or treatment modification can better the condition.

MCH Blood Test Importance

Anemia can give abnormal MCH level in MCH Blood Test report. Not only anemia, there are several medical conditions such as liver disease, Hypothyroid, Thalassemia etc. can cause abnormal MCH value in MCH blood test.

When there is either high or low MCH value it means there is some underlying health issues in your body. If the health issue is already diagnosed then MCH blood test helps to treat the condition well. If the reason is unknown, it is high time to find the cause.

MCH Blood Test Process

There is no specific test process to follow. This test is done through simple blood sample. Just like basic hemoglobin test this test also do not require any restrictions in food, drinks or in timing.

MCH Blood Test Normal Range

MCH Blood Test normal range is (30 ± 3) pg

On average, MCH Blood Test range is between 27.5 pg to 33.2 pg

MCH Blood Test value in female is usually lower than male due to loss of blood during periods (menstruation).

MCH Blood Test Low Level

If your MCH Blood test value is below 27 pg then it is considered as low MCH both in man and woman. Most common cause of MCH blood test low value is the anemia due to iron deficiency. The causes of MCH low level are

  • Lack of iron in body- Lack of iron causes low MCH because, iron helps to make hemoglobin, so when there is iron deficiency hemoglobin production is low. As a result MCH becomes low. There are many reasons of iron deficiency in our body like low dietary intake of iron, decreased absorption of iron in our body, etc.
  • Pregnancy- In pregnancy there is increased demand of iron. So it is very common to have iron deficiency during pregnancy. If the intake of iron is not enough as per demand, the deficiency of iron causes low MCH.
  • Blood loss- Blood loss can causes low MCH. Because due to blood loss, there is loss of red blood cell (RBC) from blood circulation. With less RBC the hemoglobin becomes less in body. So the MCH value becomes low.
  • Thalassemia- in this disease, the hemoglobin production is less in body. So MCH value is low.

MCH Blood Test High Level

When the MCH Blood Test value is more than 33 pg then it is considered as high MCH for both man and woman.

Anemia with high MCH is called Macrocytic Anemia. Here red blood cells (RBC) are larger than normal. Anemia with high MCH occurs due to

  • Vitamin B12 deficiency
  • Folic acid deficiency
  • Liver disease
  • Hypothyroidism
  • Too much alcohol intake
  • Myelodysplastic Syndrome
  • Drugs that are used for the treatment of cancer, autoimmune diseases, diabetes, seizure, etc.

MCH Blood Test Low Treatment

Treatment depends upon the cause. So, if you have low MCH due to iron deficiency, then iron rich foods in diet and iron supplements can help. Adding Vitamin C in your diet also helps for iron absorption. If symptoms are severe in low MCH due to blood loss, rarely blood transfusion is needed.

Here it is important to note that do not take iron supplements if you do not have iron deficiency. Because then iron load inside your body will become more and it damages organs.

MCH Blood Test High Treatment

If you have high MCH and it is due to Vitamin B12 and Folic acid deficiency, the taking of foods rich with vitamin B12 and folic acid usually helps. Supplements of Vitamin B12 and Folic Acid is also helpful.

Treating the cause is very important. If you have liver disease, thyroid problems then treating those conditions are crucial. If you consume too much alcohol, then limiting the amount of consumption is vital.

If you are taking drugs that are causing high MCH such as diabetes, cancer, autoimmune diseases etc. then your doctor will guide you if you will stay with the same drugs or may switch to other drugs.


  1. William’s Hematology Book, 9th Edition
  2. Harrison’s Principles of Internal Medicine 20th edition
  3. Davidson’s Principles and Practice of Medicine 23rd edition
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