Low MCH: What It Means & What to Do

Low MCH means that your blood has difficulty carrying oxygen throughout the body. It is a common sign of anemia, especially anemia caused by iron deficiency or thalassemia, which is a genetic type of anemia.

Mean corpuscular hemoglobin (MCH) is considered low when it is below 26 picograms in adults. This result may indicate hypochromia, a condition in which red blood cells are paler than normal because they contain less hemoglobin.

To identify the cause of low MCH, it is recommended to see a primary care doctor, who may order blood tests and suggest the most appropriate treatment. This may include medications, supplements, or, in more severe cases, blood transfusions.

What it means

Low MCH can be associated with several conditions, including:

1. Iron deficiency anemia

Iron deficiency anemia, which is anemia caused by a lack of iron, is the most common cause of low MCH. It can lead to symptoms such as weakness, fatigue, and pale skin.

Common causes of iron deficiency anemia include a diet low in iron, heavy bleeding, or absorption problems such as celiac disease.

What to do: It is important to consult a primary care provider, who may recommend iron supplements, iron-rich foods like meat, beans, and lentils, and evaluation for possible causes of bleeding or poor absorption.

2. Thalassemia

Low MCH can also be related to thalassemia, a genetic disorder in which the body produces less hemoglobin or lower quality hemoglobin.

This condition may cause symptoms such as paleness, fatigue, a weak immune system, and delayed growth.

What to do: Follow-up with a hematologist is recommended. Depending on the severity of the condition, treatment may involve blood transfusions, folic acid supplements, and management of possible complications.

3. Sickle cell anemia

Low MCH may also indicate sickle cell anemia, a genetic condition that changes the shape of red blood cells, making them crescent- or sickle-shaped.

These abnormal cells have difficulty circulating and have a shorter lifespan, which can cause generalized pain, weakness, and apathy.

What to do: Regular follow-up with a hematologist is important. Treatment may include medications such as hydroxyurea, blood transfusions, and, in some cases, erythrocytapheresis, a procedure that helps reduce the need for transfusions.

4. Chronic diseases

Certain chronic diseases, such as kidney failure, autoimmune disorders like lupus or rheumatoid arthritis, and cancer, can also cause low MCH.

These conditions trigger inflammation that interferes with hemoglobin production, leading to anemia of chronic disease.

What to do: Treatment focuses on managing the underlying condition. A doctor may recommend iron supplementation or medications that stimulate red blood cell production, such as erythropoietin.

5. Lead poisoning

Lead poisoning can also cause low MCH because this toxic metal interferes with hemoglobin production and can damage the bone marrow.

Symptoms of lead poisoning may include nausea, vomiting, diarrhea, and abdominal cramps.

What to do: Seek immediate medical attention for evaluation and follow-up. In more severe cases, chelation therapy may be needed to help remove lead from the body.

Low MCV and low MCH

Low MCV (mean corpuscular volume) and low MCH values help identify potential blood problems, such as different types of anemia, particularly iron deficiency anemia.

In blood tests, MCV shows the size of red blood cells, while MCH indicates the amount of hemoglobin inside them.

Low MCV, low MCH, and high RDW

When MCV and MCH are low and RDW (red cell distribution width) is high in a blood test, this usually indicates microcytic anemia, which includes several types of anemia.

This combination of results helps doctors distinguish between types of anemia, such as iron deficiency anemia and thalassemia.

How to know if MCH is low

To determine if your MCH is low, it is necessary to see a primary care doctor, who will order a complete blood count (CBC).