Everything You Need to Know About the MCH Blood Test

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Blood tests are essential tools in healthcare, helping doctors diagnose various conditions and monitor overall health. One of these tests is the MCH blood test. But what does this test measure, and why is it important? In this detailed guide, we'll cover everything about the MCH blood test, including its purpose, how it's done, and what your results mean for your health.

What is the MCH Blood Test?

The MCH blood test measures the mean corpuscular hemoglobin (MCH), which is the average amount of hemoglobin in each red blood cell. Hemoglobin is an essential protein found in red blood cells, responsible for transporting oxygen from the lungs to the body's tissues and organs. Knowing your MCH levels helps doctors understand how well your red blood cells are performing.

Why Hemoglobin is Important

Hemoglobin plays a vital role in the transportation of oxygen throughout your entire body.  It picks up oxygen in the lungs and delivers it to tissues and organs. If your hemoglobin levels are too low, your body won't get enough oxygen, leading to issues like fatigue and weakness, and potentially more serious conditions like anemia.

Why You Need the MCH Blood Test

The MCH blood test is important because it helps identify problems related to red blood cells and hemoglobin. It shows whether your red blood cells are carrying the right amount of hemoglobin, which is essential for your body's oxygen supply.

How is the MCH Blood Test Done?

The MCH blood test is part of a larger test called the complete blood count (CBC). Here's how it works:

  • A healthcare provider takes a small blood sample, usually from a vein in your arm.
  • The sample is sent to a lab where it's analyzed to measure various components, including MCH.

Preparing for the MCH Blood Test

Generally, no special preparation is needed for an MCH blood test. However, if it's part of a broader health assessment, your doctor might give you specific instructions. Always inform your healthcare provider about any medications or supplements you're taking, as they might affect the results.

Understanding Your MCH Blood Test Results

After your blood sample is analyzed, the results will be sent to your doctor, who will interpret them based on your overall health and medical history. The MCH value is usually measured in picograms (pg) per cell. Here's what the results might mean:

Normal Range for MCH Blood Test

The MCH blood test normal range is typically between 27 and 33 picograms (pg) per cell. This range can slightly vary depending on the lab and the population being tested. Results within this range mean your red blood cells have a normal amount of hemoglobin.

Low MCH Blood Test Results

If your MCH blood test results are below the normal range, it might indicate microcytic anemia, where red blood cells are smaller and have less hemoglobin. Causes of low MCH levels include:

  • Iron deficiency anemia: The most common type of anemia, often due to not getting enough iron in your diet or poor iron absorption.
  • Thalassemia: A genetic disorder affecting hemoglobin production.
  • Chronic diseases: Conditions like chronic kidney disease can impact red blood cell production and hemoglobin levels.

High MCH Blood Test Results

A high MCH blood test result means your red blood cells have more hemoglobin than average, a condition called macrocytic anemia. Causes include:

  • Vitamin B12 deficiency: Essential for red blood cell production, a lack of B12 can lead to larger red blood cells.
  • Folate deficiency: Like B12, folate is crucial for making red blood cells.
  • Liver disease: Conditions affecting the liver can impact red blood cell size.
  • Hypothyroidism: An underactive thyroid can affect various body functions, including red blood cell production.

Symptoms of Abnormal MCH Levels

Abnormal MCH levels, whether high or low, can cause various symptoms. Recognizing these symptoms is important to seek medical help.

Symptoms of Low MCH Levels

Fatigue and Weakness: Due to low oxygen delivery to tissues.
Pale Skin: A common sign of anemia.
Shortness of Breath: Even with mild activity, due to reduced oxygen-carrying capacity.
Feeling dizzy or lightheaded, particularly upon quickly standing up.

Symptoms of High MCH Levels

  • Fatigue: Similar to low MCH levels, due to poor oxygen use.
  • Difficulty Concentrating: Lack of oxygen can affect brain function.
  • Shortness of Breath: Noticeable during physical activities.
  • Heart Palpitations: Irregular heartbeats as the body tries to compensate for low oxygen.

Causes of Abnormal MCH Levels

Knowing the causes of abnormal MCH levels is crucial for effective treatment.


Causes of Low MCH Levels

  • Nutritional Deficiencies: Not enough iron, vitamin B12, or folate.
  • Chronic ailments such as persistent kidney disease or rheumatoid arthritis.
  • Genetic Disorders: Thalassemia or other inherited conditions affecting hemoglobin production.
  • Blood Loss: Acute or chronic, from injuries, surgeries, or internal bleeding.

Causes of High MCH Levels

  • Vitamin Deficiencies: Especially B12 and folate.
  • Liver Disease: Impaired liver function affecting red blood cell production.
  • Thyroid Disorders: Hypothyroidism affecting metabolic processes.
  • Medications: Some drugs can alter red blood cell size and hemoglobin content.

Treatment for Abnormal MCH Levels

Treatment depends on the underlying cause of abnormal MCH levels. Here are common approaches:


Treating Low MCH Levels

  • Iron Supplements: For iron deficiency anemia.
  • Vitamin B12 Injections or Supplements: For B12 deficiency.
  • Folate Supplements: To address folate deficiency.
  • Dietary Changes: Eating more iron-rich foods like red meat, beans, and leafy greens.
  • Treating Underlying Conditions: Managing chronic diseases affecting red blood cell production.

Treating High MCH Levels

  • Vitamin B12 and Folate Supplements: To correct deficiencies.
  • Addressing Liver Disease: Treating liver conditions.
  • Thyroid Hormone Replacement: For hypothyroidism.
  • Medication Adjustments: Changing or stopping drugs affecting red blood cell production.

Monitoring and Follow-Up

Regular monitoring of MCH levels is essential for managing conditions affecting hemoglobin and red blood cells. Follow-up tests and consultations with your doctor ensure that your treatment plan is effective and adjust it as needed.


The MCH blood test is a key diagnostic tool providing important information about your red blood cells and hemoglobin levels. Understanding your MCH levels helps diagnose and manage health conditions, ensuring your body gets the oxygen it needs. Whether your MCH levels are low, high, or normal, working with your healthcare provider to interpret the results and find the best treatment is crucial for maintaining good health.

By staying informed about your health and understanding the significance of the MCH blood test, you can take important steps to ensure your well-being and address any underlying health issues promptly. If you experience symptoms of abnormal MCH levels, seek medical advice and get the necessary tests to understand your health better.