Mean Corpuscular Hemoglobin Concentration (MCHC) is a value found in a complete blood count (CBC) test, indicating the average concentration of hemoglobin within red blood cells. A low MCHC result can be concerning, suggesting a potential issue with red blood cell health. This article clarifies what a low MCHC means, its common causes, and how to address it.
Understanding MCHC
MCHC defines the average concentration of hemoglobin inside your red blood cells. Hemoglobin, an iron-containing protein, gives blood its red color and transports oxygen from the lungs to tissues, carrying carbon dioxide back for expulsion.
A normal MCHC range for adults typically falls between 32 to 36 grams per deciliter (g/dL), though these values can vary slightly among different laboratories. This measurement is one of several red blood cell indices included in a CBC, providing a comprehensive picture of red blood cell characteristics.
What Low MCHC Indicates
A low MCHC value indicates red blood cells contain a reduced concentration of hemoglobin. This condition, medically termed hypochromia, means red blood cells appear paler than usual under a microscope. Low MCHC often occurs alongside microcytosis, where red blood cells are also smaller than their typical size.
These characteristics—paleness and small size—suggest the body is not effectively producing or utilizing hemoglobin. Since hemoglobin binds and transports oxygen, a lower concentration within red blood cells diminishes their oxygen-carrying capacity. This points towards conditions affecting hemoglobin synthesis or iron availability.
Common Causes of Low MCHC
The most common reason for a low MCHC is iron deficiency anemia. Iron is essential for hemoglobin production, and its lack directly impacts hemoglobin concentration in red blood cells. This deficiency can stem from inadequate dietary intake, issues with iron absorption (e.g., celiac disease, gastric bypass surgery), or chronic blood loss (e.g., heavy menstrual periods, gastrointestinal bleeding).
Thalassemia, a group of inherited blood disorders, is another cause. In thalassemia, genetic defects lead to the body producing less hemoglobin than normal. While mild forms may require little treatment, severe types significantly reduce hemoglobin concentration.
Chronic diseases can also contribute to low MCHC, leading to anemia of chronic inflammation. Long-standing conditions like kidney disease, certain cancers, or autoimmune inflammatory diseases interfere with the body’s ability to utilize iron effectively, even with adequate iron stores. This impaired iron use results in reduced hemoglobin synthesis and a lower MCHC.
Addressing Low MCHC
When a low MCHC is identified, further diagnostic steps determine the underlying cause. A complete blood count (CBC) is usually the initial test. If MCHC is low, additional evaluations like serum iron and ferritin levels are often performed to check for iron deficiency. If a genetic condition like thalassemia is suspected, specific tests such as hemoglobin electrophoresis may be necessary.
Treatment for low MCHC depends on the diagnosed cause. For iron deficiency anemia, the primary approach involves iron supplementation, often with oral tablets, to replenish the body’s iron stores. Dietary adjustments to include iron-rich foods like lean meats, leafy greens, and fortified cereals are also recommended. Vitamin C may be advised alongside iron to enhance absorption.
Managing thalassemia may involve regular blood transfusions to maintain healthy hemoglobin levels, especially in severe forms. Patients undergoing frequent transfusions might also need chelation therapy to remove excess iron that can build up in the body. For anemia of chronic disease, managing the underlying inflammatory condition is the main treatment strategy, as this can improve the body’s ability to produce red blood cells. Consulting a healthcare professional is important for proper diagnosis and a personalized treatment plan.