Unit Converter
MCHC – Mean Corpuscular Hemoglobin Concentration
(Average Concentration of Hemoglobin Within a Single Red Blood Cell)
Synonyms
- MCHC
- Mean corpuscular hemoglobin concentration
- Mean cell hemoglobin concentration
- RBC hemoglobin concentration
Units of Measurement
- g/dL
- g/L
- g/100 mL
- g%
- mg/mL
- mmol/L
- µmol/L
- % (used rarely in older literature)
Molecular Weight of Hemoglobin
Hb ≈ 64,500 g/mol
Key Unit Conversions
Mass Units
1 g/dL=10 g/L1\ \text{g/dL} = 10\ \text{g/L}1 g/dL=10 g/L 1 mg/mL=1 g/dL1\ \text{mg/mL} = 1\ \text{g/dL}1 mg/mL=1 g/dL \text{g%} = \text{g/dL} g/100 mL=g/dL\text{g/100 mL} = \text{g/dL}g/100 mL=g/dL
Molar Units
mmol/L=g/L64.5\text{mmol/L} = \frac{\text{g/L}}{64.5}mmol/L=64.5g/L µmol/L=g/L0.0645\text{µmol/L} = \frac{\text{g/L}}{0.0645}µmol/L=0.0645g/L
Example
- MCHC 33 g/dL
= 330 g/L
≈ 5.12 mmol/L
≈ 5120 µmol/L
%
Older conversion:
\text{%} = \text{g/dL} \times 1
So 33 g/dL = 33% (this is outdated but still used in some texts).
Description
MCHC is the average concentration of hemoglobin inside an RBC.
It reflects chromicity (color) of red cells and is essential in anemia classification.
Formula:
\text{MCHC} = \frac{\text{Hemoglobin (g/dL)}}{\text{Hematocrit (L/L)}} \quad \text{or} \quad \text{MCHC} = \frac{\text{Hb (g/dL)}}{\text{Hct (%)}} \times 100
Interpreted together with:
- MCV
- MCH
- RDW
- Smear morphology
Physiological Role
MCHC is not a biological substance but a diagnostic index that reflects:
- Efficiency of hemoglobinization
- Severity of microcytosis/hypochromia
- Structural RBC defects (e.g., spherocytosis)
Clinical Significance
LOW MCHC
(Most common abnormality)
Causes
- Iron Deficiency Anemia (IDA) - hallmark
- Thalassemia (trait or major)
- Anemia of Chronic Disease (mildly low or normal)
- Sideroblastic Anemia
- Lead Poisoning
- Chronic blood loss
- Late pregnancy iron deficiency
Pattern
- Low MCHC
- Low MCV
- Low MCH
- High RDW (in IDA, not in thalassemia)
Clinical Meaning
Cells contain less hemoglobin per volume, giving a pale (hypochromic) appearance on smear.
HIGH MCHC
(Far less common - important red flag)
Causes
- Hereditary Spherocytosis (classic cause)
- Spherocytes are smaller with higher hemoglobin concentration
- Spherocytes are smaller with higher hemoglobin concentration
- Autoimmune Hemolysis (spherocytes formed due to antibody-mediated membrane loss)
- Cold agglutinins (false ↑ MCHC due to clumping → low Hct)
- Severe Burns
- Dehydration (hemoconcentration)
- Hyperlipidemia / High bilirubin (laboratory artifact)
Pattern
- MCHC > 36 g/dL is unusual and suggests:
- Analytic interference
- Membrane defect (spherocytosis)
- Cold agglutinins
- Analytic interference
Reference Intervals
(WHO + Tietz 8E + Mayo + ARUP)
Adults
- 32 – 36 g/dL
(= 320 – 360 g/L)
(= 4.96 – 5.58 mmol/L)
Children
- 30 – 36 g/dL
Infants
- 28 – 36 g/dL
Critical Flags
- MCHC > 36.5 g/dL → suspect spherocytosis or lab artifact
- MCHC < 30 g/dL → significant hypochromia (iron deficiency, thalassemia)
Diagnostic Uses
1. Classification of Microcytic Anemia
Low MCHC → iron deficiency or thalassemia.
2. Identify Spherocytosis
High MCHC + spherocytes on smear.
3. Detect Laboratory Artifact
High MCHC suggests:
- Lipemia
- Cold agglutinins
- Severe hyperbilirubinemia
4. Guide Iron Therapy Monitoring
Rising MCHC = improving hemoglobinization.
5. Evaluate Hemolysis
High MCHC with hemolysis markers (LDH, bilirubin, reticulocytes).
Analytical Notes
- Automated analyzer-derived value
- Falsely high MCHC occurs in:
- Cold agglutinins
- Lipemia
- Hyperbilirubinemia
- Cold agglutinins
- Falsely low MCHC in severe dilution or marked microcytosis
- Always confirm with manual smear review if suspicious
Clinical Pearls
- MCHC rarely exceeds 36 g/dL - when it does, think spherocytosis or cold agglutinins.
- Low MCHC is the earliest change in iron deficiency.
- In thalassemia trait: very low MCHC + normal RDW.
- MCHC normal but MCV low? → early iron deficiency or ACD.
- Always interpret MCHC with MCV + MCH for full anemia classification.
Interesting Fact
MCHC reflects hemoglobin concentration, not total hemoglobin content - making it the RBC analogue to “hematocrit-adjusted hemoglobin density.”
References
- Tietz Clinical Chemistry & Molecular Diagnostics, 8th Edition - Hematology Indices
- WHO Hematology Reference Intervals
- Mayo Clinic Laboratories - CBC Indices
- ARUP Consult - RBC Morphology & CBC Interpretation
- MedlinePlus / NIH - RBC Indices
