MCHC: Definition and Normal Values
MCHC (Mean Corpuscular Hemoglobin Concentration) measures the concentration of hemoglobin in a given volume of packed red blood cells, with normal values ranging from approximately 32-36 g/dL. 1, 2
What MCHC Represents
- MCHC is a standard parameter reported in complete blood counts by automated analyzers that quantifies hemoglobin concentration per unit volume of red blood cells 2
- It serves as one of the key red blood cell indices used alongside MCV (Mean Corpuscular Volume) and MCH (Mean Corpuscular Hemoglobin) for anemia classification 1, 3
- Values significantly above the reference range are not physiologically possible due to hemoglobin solubility limitations 2
Normal Reference Values
The normal MCHC range is approximately 32-36 g/dL (or 19.8-22.3 mmol/L), though this can vary slightly between laboratories 1, 4
- The reference range has been validated across MCV values from 30 to 120 fL and MCHC values from 27 to 45 g/dL in research settings 4
- Current automated methods accurately measure hemoglobin concentration over a range of 27 to 35 g/dL 4
Clinical Significance of Abnormal Values
Low MCHC (Hypochromic Cells)
- Low MCHC specifically indicates hypochromic red blood cells with decreased hemoglobin content, reflecting severe iron-restricted erythropoiesis 5, 6
- Iron deficiency anemia is the most important cause of chronically low MCHC and requires comprehensive gastrointestinal evaluation to exclude malignancy in adult men and post-menopausal women 5
- Other causes include thalassemia minor (distinguished by normal or low RDW <14.0%), chronic inflammatory conditions, and rarely sideroblastic anemia 5, 6
High MCHC
- Elevated MCHC can provide clues to certain types of hemolytic anemia and necessitates critical evaluation of the peripheral blood smear 2
- False elevations can occur due to cold agglutination or lipid interference, requiring correction with 37°C water bath or plasma exchange 3
Essential Diagnostic Context
MCHC should always be interpreted alongside other complete blood count parameters including MCV, RDW, and reticulocyte count, plus serum ferritin and CRP 1, 5
- Measuring hemoglobin and hematocrit alone without iron status indicators can miss iron depletion and lead to misdiagnosis of individuals as normal when they are actually iron-deficient 7
- The minimum workup for anemia must include red blood cell indices (RDW, MCV), reticulocyte count, serum ferritin, transferrin saturation, and CRP concentration 1, 5