MCH Blood Test: Causes, Symptoms, and Treatment

The mean corpuscular haemoglobin or MCH blood test is a vital component of routine check-ups, measuring the average level of haemoglobin in your red blood cells.

Abnormal MCH levels can indicate symptoms of anaemia, such as fatigue and weakness, which are often linked to inadequate blood cell production or vitamin deficiencies.

What is MCH?

MCH (mean corpuscular haemoglobin) measures the average amount of haemoglobin per red blood cell.

Haemoglobin is a key protein in red blood cells. It carries oxygen and nutrients to different parts of the body. The oxygen fuels your cells and helps your body work properly.

An MCH test is commonly done during a complete blood count (CBC) test. It relates to two other values:

• Mean corpuscular volume (MCV) and

• Mean corpuscular haemoglobin concentration (MCHC).

Together, MCV, MCH and MCHC are referred to as red blood cell indices to allow healthcare providers to diagnose blood disorders.

One of the primary conditions MCH can help diagnose is anaemia, which occurs when the body produces too few healthy red blood cells. This deficiency can lead to a limited supply of oxygen-rich blood throughout the body, resulting in symptoms such as fatigue and weakness.

When is MCH required for a blood test?

MCH is included in the CBC test, which evaluates the health of red blood cells, white blood cells, and platelets. Finding your MCH level can help your doctor identify any potential conditions early.

MCH-based medical diagnosis is particularly appropriate if the patient shows signs of anaemia such as tiredness and headache.

Along with the other RBC indices, an abnormal MCH can indicate the presence and type of anaemia the patient has. In addition, it can suggest the most probable cause of anaemia.

How is an MCH done?

The MCH blood test is performed through a simple blood draw. Your healthcare provider, such as a nurse or phlebotomist, will collect blood from a vein in your arm.

The blood sample is then analysed using an automated blood counter, which measures MCH levels and provides detailed information about your red blood cells.

How do I prepare?

No special preparation is needed for blood testing to measure MCH levels. If your healthcare provider wants to do extra blood tests, you might need to fast first.

The duration of your fasting will depend on what the tests require, so it is best for you to discuss this with your healthcare provider before blood collection. Follow their instructions to ensure you’re ready.

MCH levels

MCH levels indicate the average amount of haemoglobin present in a single red blood cell.

The measurement of MCH is important for diagnosing and managing underlying conditions related to RBCs, such as anaemia.

Normal MCH levels typically range between 26 and 33 picograms per red blood cell.

What is a CBC test?

A Complete Blood Count (CBC) test is a comprehensive blood analysis that measures the quantity and size of red blood cells, white blood cells, and platelets.

It is one of the most common routine blood tests that doctors use to assess a patient's overall health. The CBC test is often performed to:

• Look at overall health conditions 

• Detect possible causes of symptoms such as weakness, fatigue, fever, easy bruising and prolonged bleeding

• Check on medical treatment that can possibly affect red blood cells

What does low MCH mean?

Low MCH levels indicate that there is an insufficient amount of haemoglobin in your red blood cells. This can lead to conditions like hypochromic anaemia, where red blood cells appear paler than usual, or microcytic anaemia, in which red blood cells are abnormally small.

Both conditions are indicative of inadequate oxygen-carrying capacity in the blood.

Causes of low MCH levels

Here are the primary causes of low MCH levels:

• Iron deficiency anaemia: 

  • This condition is the most common cause of low MCH. When your body lacks enough iron, it can’t produce sufficient haemoglobin, which is essential for transporting oxygen in the blood. It is most commonly due to blood loss from heavy menstrual bleeding and excessive bleeding in traumatic accidents and surgery.

• Haemoglobinopathies: 

  • Certain blood disorders can disrupt the production of normal haemoglobin, leading to low MCH levels. Conditions such as thalassaemia and sickle cell anaemia are examples where the body is unable to produce adequate or functional haemoglobin, affecting overall red blood cell health.

• Inflammation associated with chronic medical conditions: 

  • Long-term inflammation associated with chronic disease, such as chronic kidney disease, liver disease, and certain cancers, can also lead to low MCH levels.

Symptoms of Low MCH

Low MCH levels can lead to anaemia, and the symptoms may include:

• Fatigue and weakness

• Shortness of breath

• Dizziness and Syncope

• Chest pain 

• Fast and irregular heartbeat

• Pale or yellowish skin 

What does high MCH mean?

High MCH levels indicate that each red blood cell contains more haemoglobin than usual. This can be a sign of macrocytic anaemia, a condition where red blood cells are larger than normal.

Causes of high MCH levels

It occurs because your body is not getting enough folate or vitamin B12 to make healthy red blood cells. 

The following can lead to high MCH scores:

• Chronic alcohol use 

• Thyroid gland disorder

• Medications or medical treatment, such as chemotherapy, can interfere with the body's ability to absorb essential nutrients like folate or vitamin B12, potentially causing an increase in MCH levels.

Symptoms of High MCH

High MCH also causes anaemia. Symptoms of high MCH are

• Fatigue and weakness

• Shortness of breath

• Dizziness and Syncope

• Chest pain 

• Fast and irregular heartbeat

• Pale or yellowish skin

If you experience any of these symptoms or suspect low or high MCH levels, it is important to consult a healthcare professional for proper evaluation and management.

To take charge of your health, book an appointment with Thomson Medical, to meet our medical specialists and discuss a personalised treatment plan.

How Are Abnormal MCH Levels Treated?

Abnormal MCH levels, whether high or low, are treated differently depending on the underlying disease or medical condition causing the imbalance.

To begin, your healthcare provider will conduct a thorough assessment by gathering detailed information about your health history as well as your family’s health background. They will review the results of your complete blood count test to gain a comprehensive understanding of your blood health.

If the results indicate the presence of anaemia, your provider will determine the specific type of anaemia and its causes. Depending on the findings, further testing may be necessary to evaluate other potential conditions. Throughout this process, your healthcare provider will guide you to ensure an accurate diagnosis and develop a tailored treatment plan aimed at restoring your MCH levels to normal.

FAQ

What does MCV and MCHC levels mean?

MCV measures the average size of your red blood cells. MCHC measures the average hemoglobin concentration per red blood cell. 

Is it better to have high or low MCH?

Neither high nor low MCH is better; both can lead to anaemia. The MCH result shows the average number of picograms (one trillionth of a gram) of haemoglobin you have per red blood cell. The normal MCH range for adults is 27-33 pg/cell. Values below this range indicate low MCH, while values above indicate high MCH. Both abnormally high and low MCH levels can lead to anaemia Thus, it is important to maintain a normal range of MCH.

Can stress cause high MCH?

Stress does not directly affect MCH. However, chronic stress may indirectly impact your health by affecting the absorption of essential nutrients like folate and vitamin B12. Deficiencies in these nutrients can impair the production of healthy red blood cells. Thus, it is important to manage stress effectively and maintain a healthy, balanced diet. 

Can high MCH cause weight gain?

Yes, high levels of MCH in the blood can lead to weight gain, especially if the high levels are chronic.

Is MCH affected by dehydration?

Yes, dehydration can affect MCH levels. When dehydrated, the blood becomes more concentrated due to reduced plasma volume, potentially causing an apparent increase in MCH. This condition makes red blood cells appear more concentrated with haemoglobin. It’s important to be properly hydrated when getting a blood test to ensure accurate results.

How do I improve my MCH?

Most often, low MCH is caused by iron deficiency anaemia. To avoid iron deficiency anaemia, you can increase iron-rich foods in your diet. You can take iron and vitamin C supplements to improve iron absorption in your body. 

The high MCH value is associated with low levels of folate or vitamin B12. Avoid iron blockers such as caffeinated drinks, alcohol, and foods with phytates or calcium. Iron blockers should be avoided or taken separately from iron-rich foods. 

To reduce the deficiency of folate or vitamin B12, it is required to increase the intake of folate (found in liver and green, leafy vegetables) or vitamin B12-enriched diets. You may take folate and vitamin B12 supplements. 

Does fasting affect MCH?

Fasting does not directly affect MCH levels. However, inappropriate or prolonged fasting may impact a healthy balanced diet by restricting the amount of iron, vitamin C, folate, and vitamins that your body is taking in. Not getting enough of these nutrients over time may raise the risk of anaemia. So, it’s important to keep a balanced diet while fasting.

The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations based on your medical conditions, request an appointment with Thomson Medical.