What Are MCH (Mean Corpuscular Hemoglobin) Levels?

Medically Reviewed by Zilpah Sheikh, MD on March 26, 2024
5 min read
What Severe Asthma Looks LikeAn asthma attack can be serious and scary. Here’s what happens to your airways and why it’s hard to breathe.78

[MUSIC PLAYING]

SPEAKER: An asthma attack

happens when you are exposed

to an allergen

or some other trigger,

like a virus, cold air,

exercise, stress,

or environmental pollutants.

Your airway's become

inflamed and swollen,

and the muscles in your chest

tighten.



Your breathing tubes become

narrow, and make extra mucus,

making it hard to get enough air

into your lungs.

Your airways start to overreact,

causing spasms that lead

to wheezing and coughing.



A severe asthma attack can cause

shortness of breath,

and a tight feeling

in your chest.

Your skin may pull in slightly

between your ribs.

You may have hunched shoulders,

and strained abdominal and neck

muscles.

Your face and lips may have

a blue tint.

And you may feel confused,

agitated,

or unable to concentrate.



A severe asthma attack can be

life threatening.

If your symptoms aren't

improving with home treatment,

see a doctor right away.

<p>Medscape: "Asthma."<br/>Mayo Clinic: "Asthma Attack."<br/>Asthma and Allergy Foundation of America: "What are the symptoms of Asthma?"</p>/delivery/8c/51/8c51cdc3-eaea-43b5-9435-12d440ee7a1d/vd-2276-what-severe-asthma-looks-like_,4500k,1000k,400k,2500k,750k,.mp402/08/2018 12:21:00 PM650350what severe asthma looks like video/webmd/consumer_assets/site_images/article_thumbnails/video/what_severe_asthma_looks_like_video/650x350_what_severe_asthma_looks_like_video.jpg091e9c5e81903d1a

You might hear your doctor talk about MCH levels when they explain the results of certain blood tests. MCH is short for "mean corpuscular hemoglobin." It's the average amount of a protein called hemoglobin in each of your red blood cells. Hemoglobin carries oxygen around your body.

It's possible you'll learn about MCH when you get a blood test called a CBC (complete blood count). This test measures different parts of your blood, including red blood cells and white blood cells. Doctors use information from the CBC to calculate your MCH.

Your doctor may use this measurement to help in a diagnosis of some nutrient deficiencies or problems with your liver. 

A CBC measures the different cells that make up your blood, including your:

  • Red blood cells
  • White blood cells, which fight infection
  • Hemoglobin
  • Platelets, which help your blood clot

You may have a CBC as part of your yearly physical exam or to check for a disease. Your doctor might give you this test if you have symptoms of a condition that affects your blood cell count.

To do a CBC, a nurse puts a needle into a vein in your arm. The needle attaches to a test tube, where the blood collects. A lab then analyzes the blood sample.

 

 

MCH levels vary, so there is a range that doctors consider normal. MCH is measured in picograms per cell, or (pg/cell). For adults of all ages and children, normal MCH levels are 27 to 31 pg/cell. For newborns, they are 32 to 34 pg/cell.

The most common reasons for low MCH levels are:

Anemia. This happens when your body doesn't have enough healthy red blood cells to carry oxygen around your body. The most common cause is low levels of the mineral iron. It's also caused by low levels of vitamin B12 and folate. 

Hemoglobinopathies. These are inherited (passed down through family) blood disorders where there's a problem with the shape of hemoglobin or with how your body makes it. Thalassemia and sickle cell disease are two examples. 

Low MCH level symptoms

Your symptoms will be related to what is causing your low MCH levels.

Symptoms of anemia:

Symptoms of thalassemia:

  • Anemia symptoms
  • Abdominal swelling
  • Dark-colored pee

Symptoms of sickle cell disease:

  • Anemia symptoms
  • Dark-colored pee
  • Yellowish eyes
  • Pain and swelling in hands and feet
  • Episodes of body pain

A high MCH level means your red blood cells are larger than normal. This is called macrocytosis. Usually, there is nothing to be worried about if you have macrocytosis. But it can be caused by macrocytic anemia. If you have macrocytic anemia, your bone marrow makes red blood cells that are too large.

High MCH levels could also be caused by:

  • Some forms of liver disease 

  • Drinking too much alcohol 

  • Some blood cancers 

  • Too little vitamin B12 or folate 

  • Hypothyroidism, when your body makes too little thyroid hormone

  • Medicines, including chemotherapy medications, antibiotics, and antivirals

High MCH level symptoms

A high level of MCH itself doesn't cause symptoms and might only be found with a blood test. If you do have symptoms, they would be related to the condition that caused the high MCH levels.

For example, if you have liver disease, you might have pain in the upper part of your abdomen, loss of appetite, fatigue, or yellowing of your skin. If you have hypothyroidism, you might be tired, gain weight, have numbness and tingling in your hands and fingers, and have sore muscles. Low levels of vitamin B12 and folate can cause symptoms of anemia, like fatigue, dizziness, and shortness of breath.

Your doctor can find out if your MCH levels are too high or low through a blood test. There are several causes for abnormal MCH levels. Some are common, such as anemia and medication side effects. But they can also be caused by illnesses such as blood cancers or inherited blood disorders. Your treatment plan will depend on the cause.