Mean Corpuscular Hemoglobin Concentration (MCHC)
How concentrated the hemoglobin is inside your red blood cells, which shows how pale or dense they are.
AI-verified against cited sources. Awaiting expert reviewAlso called MCHC, CHCM, CCMHLOINC 786-4
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What it is
Mean corpuscular hemoglobin concentration (MCHC) tells you how packed with hemoglobin the average red blood cell is. Hemoglobin is the protein that carries oxygen. Your lab calculates MCHC from your hemoglobin and hematocrit, and it is usually reported in grams per deciliter (g/dL). Some countries print it in g/L, so 33 g/dL appears as 330 g/L. The number stays in a narrow band because red cells cannot hold much more hemoglobin than they normally do.
Why it matters
A low MCHC means red cells are paler than usual (hypochromic). This is most often linked to low iron or to thalassemia trait, an inherited difference in hemoglobin that usually causes no symptoms. A high MCHC is less common. When it is real, it can be seen in conditions where red cells are small and dense, such as hereditary spherocytosis. More often, a very high MCHC comes from the sample or the instrument, so labs often re-run these samples.
If it’s low
A low MCHC means red cells hold less hemoglobin for their size, so they look pale under a microscope. This is called hypochromia. It usually goes along with a low MCV and a low MCH.
Common causes
- Low iron stores or iron deficiency anemia
- Thalassemia trait, an inherited difference in hemoglobin that usually causes no symptoms
- Long-term inflammation or chronic disease, in some people
- Slow blood loss, such as heavy periods or bleeding in the digestive tract, which can lead to low iron
- Lead exposure or less common blood conditions
What can help
- Ask whether a ferritin test (a measure of iron stores) is a good next step
- Tell your clinician about heavy periods, blood in your stool or black stools
- If your ferritin is normal, ask whether more testing for thalassemia trait is worthwhile
If it’s high
A high MCHC is uncommon, and it is often not real. Hemoglobin gets close to its limit of how much can be packed into a cell at around 37 g/dL, so very high values usually come from the sample or the instrument. When a high value is real, it can reflect red cells that are small and dense. A clinician can look at it with your other results.
Common causes
- Sample or instrument effects, such as cold agglutinins (red cells clumping in a cool tube), cloudy (lipemic) plasma or red cells breaking down in the tube
- Hereditary spherocytosis, an inherited red cell condition that makes the cells small and round
- A few other rare red cell conditions
What can help
- Ask whether the sample could have affected the result and whether a repeat test makes sense
- If the value stays high on repeat testing, ask whether a blood smear or other red cell tests would help
Usual ranges
What labs print as the reference range, by who was tested. Ranges differ a little between labs, so the range on your own report is the one your result is judged against.
For adults: 32–36 g/dL. Source: MedlinePlus, National Library of Medicine, Oregon Health & Science University Lab Services, Parkview Health Laboratory, Labcorp, ARUP Laboratories, UnitsLab.
- 18+ (this one applies)32–36 g/dL
Sources: MedlinePlus, National Library of Medicine, Oregon Health & Science University Lab Services, Parkview Health Laboratory, Labcorp, ARUP Laboratories, UnitsLab
See MCHC by age and sex, with the U.S. survey numbers where they exist.
How common is your level?
NHANES describes the US civilian, non-institutionalized population, not a 'healthy' reference group. People with disease, on medication, fasting or not (except fasting-subsample markers), smokers and so on are all included. A percentile says where a value sits among Americans of that sex and age, not whether it is normal.
Use the left and right arrow keys to read each age. Shift moves five years.
Reference data derived from CDC/NCHS National Health and Nutrition Examination Survey (NHANES), cycles 2015-2016, 2017-March 2020 (pre-pandemic), August 2021-August 2023. Analysis by bloodtesttracker.com; not endorsed by CDC, NCHS or HHS.
Explore MCHC by age and sex: every percentile as a table, with a download.
What can affect your result
- Units: g/dL, g/L and % are all used, and a g/L value is about 10 times the g/dL number
- Age: infants and young children have lower ranges, so adult ranges do not apply to them
- Sex: some labs print separate adult ranges for men and women, and many do not
- Iron status, thalassemia trait and long-term illness can lower it
- Cold agglutinins, cloudy plasma or sample handling can raise it falsely
- The analyzer used
- Cold agglutinins (red cells clumping in a cool sample) lower the red cell count and can make MCHC read falsely high.
- Very cloudy (lipemic) plasma can make the measured hemoglobin read falsely high, which pushes MCHC up.
- Red cells breaking down in the tube can lower the hematocrit and raise MCHC.
- Reports from different countries use different units (g/dL, g/L or %), so check the unit before comparing.
- Different analyzers can read the same blood slightly differently.
Weeks to a few months. Red blood cells live for roughly 3 to 4 months, so MCHC shifts only as old cells are replaced.
When to talk to a clinician
A mildly low MCHC with a normal hemoglobin is usually something to bring up at a routine visit. If your MCHC is flagged high, ask whether the sample can be re-run, since sample effects are a common cause. Contact a clinician soon if your hemoglobin is also low (below 13 g/dL in men or 12 g/dL in women, the WHO anemia cutoffs), or if you have unusual tiredness, shortness of breath, pale skin or yellowing of the skin or eyes. Call 911 or your local emergency number for chest pain, fainting or severe shortness of breath.
Questions you could ask
- Has my MCHC changed compared with my past results?
- What unit is my lab using for MCHC?
- Could the sample have affected this result, and should it be repeated?
- Does my MCHC fit with my MCV, hemoglobin and the rest of my blood count?
- Should we check my ferritin or other iron tests?
- Could blood loss, such as heavy periods, explain this?
Questions people ask
Why does my report show MCHC as 330 instead of 33?
Some countries print MCHC in grams per liter (g/L) instead of grams per deciliter (g/dL). 330 g/L is the same as 33 g/dL. Always check the unit next to your number.
Can MCHC be too high to be real?
Yes. Red cells cannot hold much more than about 37 g/dL of hemoglobin, so a value far above that is usually a sample or instrument effect. For example, red cells can clump in a cool sample. Labs often warm and re-run these samples.
Does a low MCHC mean I am anemic?
Not by itself. Anemia is defined by a low hemoglobin. A low MCHC describes how pale the red cells are, and it can happen with a hemoglobin in range. Your clinician reads MCHC together with hemoglobin, MCV and iron tests.
What is the difference between MCH and MCHC?
MCH is the amount of hemoglobin in the average red cell. MCHC is how concentrated that hemoglobin is. A large cell can hold more hemoglobin (higher MCH) while the concentration stays normal.
Show the science and sources
Units
- 1 g/dL = 1 g/dL
- 1 g/dL = 10 g/L
- 1 g/dL = 0.6206 mmol/L
- 1 g/dL = 1 %
Is a change real?
MCHC naturally varies about 0.95% from test to test in the same healthy person. Between two results from the same lab, a change of roughly 3% or more is unlikely to be day-to-day noise or lab variation (95% reference change value). Source: Systematic review and meta-analysis of within-subject and between-subject biological variation estimates of 20 haematological parameters (Coskun A et al., EFLM WG-BV).
For clinicians and researchers
MCHC is calculated: MCHC (g/dL) = Hb (g/dL) × 100 ÷ Hct (%), or equivalently MCH (pg) × 100 ÷ MCV (fL). On current analyzers hematocrit is itself calculated as MCV × RBC, so errors in the RBC count or MCV carry straight into MCHC. Hemoglobin cannot be packed much beyond roughly 37 g/dL inside a red cell, and values above 40 g/dL point to an instrument or sample problem, so a very high MCHC is usually an artifact. Cold agglutinins clump red cells, which lowers the RBC count and Hct and raises MCV and MCHC. One laboratory protocol re-runs samples with MCHC above 385 g/L after warming, and the classical fix is pre-heating to 37 °C. Lipemia raises measured Hb, and in vitro hemolysis lowers RBC count and Hct without changing MCV, so both raise MCHC. Outside artifacts, MCHC typically rises only in spherocytosis; the British Society for Haematology 2011 guideline covers the diagnosis of hereditary spherocytosis, including the eosin-5-maleimide (EMA) binding test. Low MCHC (hypochromia) can reflect impaired hemoglobin synthesis, as in iron deficiency and thalassemia. Molar MCHC (used in some countries) uses the Hb monomer basis (16,114.5 g/mol), so 32–36 g/dL is 19.9–22.3 mmol/L. Some labs print MCHC as a percentage, which is numerically the same as g/dL.
LOINC 786-4 (primary), 28540-3. Specimen: whole-blood.
Sources
- RBC indices, MedlinePlus, National Library of Medicine
- CBC with Differential: reference ranges (OHSU Lab Services test directory), Oregon Health & Science University Lab Services
- Complete Blood Count with Differential (Parkview Laboratory test directory), Parkview Health Laboratory
- Sample report, CBC, Platelet, No Differential (test 028142), Labcorp (2020)
- Sample report, CBC With Differential/Platelet (test 005009), Labcorp
- CBC with Platelet Count and Automated Differential (ARUP test 0040003), reference intervals effective March 1, 2021, ARUP Laboratories (2021)
- MCHC: Mean Corpuscular Hemoglobin Concentration (conversion and formula reference), UnitsLab
- Guidelines for the diagnosis and management of hereditary spherocytosis, 2011 update, British Journal of Haematology (British Society for Haematology) (2011)
- Answer to Case on Crazy CBC Values (cold agglutinin disease), The Blood Project
- Prospective validation of an automatic reflex test for identifying spurious elevations of mean corpuscular haemoglobin concentration due to the presence of cold agglutinins, Scandinavian Journal of Clinical and Laboratory Investigation (2021)
- How to handle lipemic CBC samples on Sysmex hematology analyzers?, Advances in Laboratory Medicine (2025)
- Assessment of Oxidative Stress Biomarkers in Rat Blood (states the hemoglobin monomer molar mass, 16,114.5 g/mol), Bio-protocol (2023)
- Evaluation of Macrocytosis, American Family Physician (2009)
- Measurement of Red Cell Lifespan and Aging, Transfusion Medicine and Hemotherapy (2012)
AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. How we build and check these pages.