A complete blood count (CBC) is one of the most common blood tests ordered by doctors. A CBC often includes a test for MCHC, which stands for “mean corpuscular hemoglobin concentration.” Most people have never heard of MCHC, but this single value can reveal important truths about how well your blood is able to transport oxygen throughout your body and help maintain normal function.
What does an MCHC blood test measure?
MCHC measures how concentrated hemoglobin is inside your red blood cells. Hemoglobin is the iron-containing protein that carries oxygen from your lungs to the rest of your body. The test for MCHC doesn’t tell us how much hemoglobin you have overall…it just determines how densely packed hemoglobin is within each red blood cell.
Understanding your MCHC blood test
For most US laboratories, an MCHC blood test between 32 and 36 grams per deciliter (g/dL) is considered normal. While small variations exist between labs, results outside of this range are considered abnormal. An MCHC level below 32 g/dL is considered low… a result above 36 g/dL is considered high.
What causes low MCHC?
Low MCHC essentially means the concentration of hemoglobin within your red blood cells is low. The most common reason for this is iron-deficiency anemia. Our bodies need iron to build red blood cells, and a low concentration of iron can impede red blood cell production and cause low MCHC.
Another possible cause of low MCHC: Beta thalassemia, an inherited blood disorder. People with this condition often have an unbalanced production of hemoglobin.
What causes high MCHC?
Although less common, persistent high levels could indicate an underlying medical condition, including hereditary spherocytosis, a genetic condition in which red blood cells are sphere-shaped instead of disc-shaped. These cells pack hemoglobin more densely, causing the high MCHC levels, which may indicate an underlying medical issue that needs to be investigated.
Another possible cause of high MCHC: Autoimmune hemolytic anemia, which occurs when the immune system destroys red blood cells prematurely, leading to an increased hemoglobin concentration in remaining cells.
Low MCHC results are far more common. High results are rarely seen—if a patient gets consistent high MCHC results, there is a need to investigate further. Treatments for high or low MCHC are dependent on the root cause.
Keep in mind: It is not uncommon to get incorrect or inaccurate lab results, possibly because the patient was very dehydrated or the samples were handled improperly. If your result is a high MCHC level, a repeat test could rule out a lab error and help the doctor decide if the result warrants further investigations.
