Mean Corpuscular Hemoglobin Concentration - MCHC

Red blood cells, SEM. Credit: Susumu Nishinaga/Science Photo Library / Getty Images

What is the Mean Corpuscular Hemoglobin Concentration (MCHC)?

Mean corpuscular hemoglobin concentration (MCHC) is the average concentration of hemoglobin in red blood cells. It is a value you will see reported as part of a Complete Blood Count (CBC) test. MCHC is one of the red blood cell (RBC) indices, and it is used to help diagnose the type, cause, and severity of anemia.

  • Normal Range for MCHC: 32-36 grams/deciliter in adults. SI units: 334-355 gram/liter.
  • A low MCHC means that there is less hemoglobin in each red cell regardless of the size of the red cell, known as hypochromia. It is seen in iron deficiency anemia and thalassemia.
  • A high MCHC is known as hyperchromia, with a higher concentration of hemoglobin in each red cell than is normal.

What Does a Low or High MCHC Mean?

The total amount of hemoglobin in a red cell is measured in the mean cell hemoglobin (MCH)  part of the CBC, but that usually just mirrors the size of the red cells. The MCHC tells you whether those cells pack in more or less hemoglobin than usual. This results in the red cells appearing more or less red, as hemoglobin is what gives them their red color.

When MCHC is low, this can mean a person has iron-deficiency anemia. This type of anemia can be caused by insufficient iron in the diet, or the inability to absorb it or use it to make hemoglobin. Another cause is blood loss over time, such as what might occur with tumors in the colon and other parts of the gastrointestinal tract.

This long, slow blood loss can cause low iron levels and a low mean cell hemoglobin concentration.

High MCHC levels are seen in autoimmune hemolytic anemia and in burn patients. They may also occur in hereditary spherocytosis, which is a rare disorder. They are not always abnormal and are unusual.

How the MCHC Test is Performed

A CBC is a typical blood test that can tell your doctor many things about your overall health and is often done as a screening test even if there is no suspicion of disease.

It is also used to follow your condition when you are under treatment for a disease, to look for signs of anemia and infection. If you are in the hospital, it is one the tests that is done to monitor your overall condition.

Your blood is drawn in a tube that contains a few drops of anticoagulant. It is then analyzed in a Coulter counter where the blood cells pass through an aperture where they are counted, and their size is measured. The red cell count multiplied by the size produces the hematocrit number. The amount of hemoglobin is also measured after bursting the red cells. The instrument then performs a calculation by dividing the hemoglobin by the hematocrit.

If a differential is ordered, it is usually automated. The red cells may appear more pale than usual if you have a low MCHC, or darker than usual if you have a high MCHC.


Todd Gertsten, MD. "RBC indices," Medline Plus, U.S. National Library of Medicine, Updated 2/24/2014.

Complete Blood Count, American Association for Clinical Chemistry. Accessed 2/15/2016.

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