Lab result explainedBlood count (CBC)Last updated November 1, 2026

MCHC blood test: what high and low MCHC mean

Mean corpuscular hemoglobin concentration (MCHC) · Complete blood count (CBC) · reported in g/dL (some labs report %)

MCHC (mean corpuscular hemoglobin concentration) is the average concentration of hemoglobin packed inside each of your red blood cells. Most US labs call 32 to 36 g/dL normal, with the exact cut-offs varying slightly from lab to lab. The two most common reasons it is off are iron deficiency, which lowers MCHC because cells are built with too little hemoglobin, and a lab or sample artefact (lipemia, cold agglutinins, a hemolysed tube) that makes MCHC read falsely high.

MCHC is a calculated number, not a direct measurement. The analyzer divides your hemoglobin by your hematocrit, so anything that disturbs either of those two values moves MCHC with it. That is why a clinician rarely reads MCHC alone: it only makes sense next to MCV, MCH, RDW and the hemoglobin itself, and a mildly abnormal MCHC with a normal hemoglobin is very often nothing.

This page explains what MCHC measures, what the normal range is, what a high or low result usually means, which causes are common and which are rare, what tests come next, and where diet and supplements genuinely help. It is written for someone holding a report, not for a textbook, and it does not replace the clinician who ordered the test.

MCHC at a glance

  • MCHC is the average hemoglobin concentration inside your red blood cells, calculated as hemoglobin divided by hematocrit.
  • Normal range: roughly 32 to 36 g/dL for adults; labs differ by about half a gram either way.
  • Low MCHC (hypochromia) usually means iron deficiency or thalassemia trait; cells are pale because they carry less hemoglobin.
  • High MCHC is uncommon; the most frequent explanations are a sample artefact, hereditary spherocytosis or an autoimmune hemolytic anemia.
  • Dehydration does not meaningfully raise MCHC, because it raises hemoglobin and hematocrit together.
  • Next step: look at hemoglobin, MCV, MCH and RDW on the same report; a ferritin test settles most low results.

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What MCHC measures

Every red blood cell is essentially a flexible bag filled with hemoglobin, the iron-containing protein that binds oxygen. MCHC asks how concentrated that hemoglobin is: grams of hemoglobin per deciliter of packed red cells. It is reported in g/dL on most US reports and occasionally as a percentage, which is the same number.

The analyzer does not measure MCHC directly. It measures hemoglobin (by lysing the cells and reading the color of the solution) and calculates hematocrit (from the red cell count multiplied by the mean cell volume, MCV). MCHC is then hemoglobin ÷ hematocrit × 100. A related index, MCH, is the absolute mass of hemoglobin per cell (hemoglobin ÷ red cell count); MCHC adjusts that mass for cell size.

Because it is derived, MCHC is the index most prone to artefact. Anything that falsely raises hemoglobin (lipemia, very high white cell counts) or falsely lowers hematocrit (cold agglutinins clumping cells) pushes MCHC above 36 without any disease in the cells themselves. Most laboratories flag an MCHC above about 37 as a quality check and re-examine the sample before releasing the result.

Normal range for MCHC

Reference ranges vary between labs and by age, sex and pregnancy. Use the range printed on your own report.

GroupTypical range (g/dL (some labs report %))Notes
Adults32–36 g/dLMany labs use 31.5–35.5 or 33–36; check the range printed on your report.
Children32–36 g/dLSimilar to adults after infancy.
Newborns30–36 g/dLSlightly lower in the first weeks of life.
Pregnancy32–36 g/dLRange unchanged, but low values are common because of rising iron demand.

High MCHC

A high MCHC (above about 36 g/dL) means the red cells, on average, contain more hemoglobin per unit volume than usual. True high values are rare because a red cell physically cannot hold much more than about 36 to 37 g/dL of hemoglobin; above that the cell would be a crystal, not a cell.

So the first question with high MCHC is whether the number is real. Mildly high values (36 to 37) with everything else normal are usually within lab variation or a minor artefact. Values of 38 or more almost always reflect a sample problem that the lab should catch, or one of a short list of conditions in which cells lose membrane or water: hereditary spherocytosis, autoimmune hemolytic anemia, severe burns, or certain hemoglobin variants.

Common causes

  1. Lab or sample artefact (most common)

    Lipemia (a fatty, cloudy sample after a heavy meal or with very high triglycerides) and hemolysis in the tube both make hemoglobin read falsely high. Cold agglutinins, antibodies that clump red cells in the tube, make the red cell count and hematocrit read falsely low, which inflates MCHC. A very high white cell count or bilirubin can do the same. A repeat on a fresh, fasting, warmed sample usually normalizes it.

  2. Hereditary spherocytosis

    An inherited defect in the red cell membrane makes cells shed surface and become small spheres. The volume drops more than the hemoglobin does, so MCHC rises; it is one of the best screening clues for the condition, especially when RDW is also high. Family history, a mild chronic anemia, jaundice episodes and gallstones at a young age are typical.

  3. Autoimmune hemolytic anemia

    Antibodies strip pieces of membrane from red cells in the spleen, producing spherocytes with a high MCHC. The hemoglobin is usually low, reticulocytes are high, bilirubin and LDH rise, and a direct antiglobulin (Coombs) test is positive.

  4. Sickle cell disease and hemoglobin C disease

    Some sickled or hemoglobin C cells are dehydrated and dense, which raises their hemoglobin concentration. In sickle cell disease the MCHC may be high while the MCV is normal or low; in hemoglobin C disease it is often mildly high.

  5. Severe burns

    Heat damages the red cell membrane and causes cells to fragment into small spheres; the surviving cells are dense, pushing MCHC up for a few days after a major burn.

  6. Hereditary xerocytosis (dehydrated stomatocytosis)

    A rare inherited channel defect lets red cells lose potassium and water. The cells are dehydrated, so MCHC is characteristically high, usually with a mild hemolytic anemia that may be mistaken for spherocytosis.

  7. Recent marked hemoconcentration from very severe dehydration

    Ordinary dehydration raises hemoglobin and hematocrit in step and leaves MCHC alone. Only extreme hypernatremic dehydration, where water leaves the red cells themselves, nudges MCHC up, and it corrects within hours of rehydration.

Symptoms that can go with it

  • Often none; the number is an incidental finding on a routine CBC
  • Fatigue, pallor or breathlessness if there is an underlying hemolytic anemia
  • Yellowing of the eyes or skin (jaundice) during hemolysis episodes
  • Dark urine after a hemolytic episode
  • A sense of fullness under the left ribs from an enlarged spleen
  • Gallstone pain at an unusually young age (hereditary spherocytosis)

Low MCHC

A low MCHC (below about 32 g/dL) means the red cells are hypochromic: paler than normal because each one carries less hemoglobin for its size. On a blood film they look like rings with too much central pallor.

By far the most common cause is iron deficiency, because the marrow cannot make enough hemoglobin to fill the cells it produces. The second most common, particularly in people of Mediterranean, Middle Eastern, South Asian, Southeast Asian or African ancestry, is thalassemia trait. The two are separated by ferritin, RDW and the red cell count, not by MCHC alone.

Common causes

  1. Iron deficiency

    Iron is the core of the heme molecule; without enough of it the marrow makes smaller, paler cells. MCHC usually falls after MCV and MCH do, so a low MCHC often signals iron deficiency that has been present for months. Heavy periods, pregnancy, poor absorption (celiac disease, bariatric surgery, long-term acid suppression) and slow gastrointestinal blood loss are the usual sources.

  2. Thalassemia trait (alpha or beta)

    An inherited reduction in one globin chain gives small, pale cells from birth. The pattern is a low MCV and MCHC with a normal or high red cell count, a normal RDW and normal ferritin. It needs no iron and is confirmed by hemoglobin electrophoresis or genetic testing.

  3. Anemia of chronic disease or inflammation

    Long-standing inflammation (rheumatoid arthritis, inflammatory bowel disease, chronic infection, cancer, kidney disease) raises hepcidin, a hormone that locks iron inside storage cells so the marrow cannot use it. The anemia is usually mild and normochromic, but in a quarter to a third of cases the cells become mildly hypochromic.

  4. Pregnancy

    Iron demand roughly doubles in the second and third trimesters, and plasma volume expands faster than red cell mass. Both tend to lower hemoglobin and, if iron stores run short, MCHC.

  5. Medications that reduce iron absorption or cause bleeding

    Proton pump inhibitors and H2 blockers lower stomach acid, which is needed to absorb non-heme iron. Aspirin, NSAIDs, anticoagulants and SSRIs increase slow gastrointestinal blood loss. The effect shows up over months, not days.

  6. Lead poisoning

    Lead blocks several enzymes in the heme synthesis pathway, so cells are made with less hemoglobin. Basophilic stippling on the blood film and a raised blood lead level confirm it; the risk is highest in children in older housing and adults with occupational exposure.

  7. Sideroblastic anemia

    The marrow has iron but cannot build it into heme, so iron piles up in ring-shaped deposits around the nucleus of developing cells. It can be inherited or caused by alcohol, isoniazid, linezolid, chloramphenicol or copper deficiency; ferritin is typically high rather than low.

  8. Copper deficiency

    Copper is needed to move iron out of storage and into the marrow. Deficiency after bariatric surgery, with excessive zinc supplementation, or on long-term tube feeds produces an iron-deficiency-like picture that does not respond to iron.

  9. Sample artefact

    Blood that sits for many hours before analysis lets red cells swell, which raises MCV and lowers MCHC. Very high blood glucose does the same by drawing water into cells. Neither reflects anything about your marrow.

Symptoms that can go with it

  • Tiredness and reduced exercise tolerance
  • Pale skin, inner eyelids or nail beds
  • Breathlessness on stairs or hills
  • Headaches, dizziness or feeling faint on standing
  • Cold hands and feet
  • Brittle or spoon-shaped nails, hair shedding, cracks at the corners of the mouth (iron deficiency)
  • Restless legs at night or cravings for ice (pica), both typical of iron deficiency
  • Palpitations or a racing heart

Read it alongside

  • Hemoglobin — tells you whether there is an anemia at all; an abnormal MCHC with a normal hemoglobin rarely needs treatment.
  • MCV — low MCV plus low MCHC points to iron deficiency or thalassemia trait; normal MCV with high MCHC points toward spherocytes.
  • MCH — moves in the same direction as MCHC in iron deficiency; MCH low with MCHC normal is early iron deficiency.
  • RDW — high RDW with low MCHC favors iron deficiency; normal RDW favors thalassemia trait. High RDW with high MCHC favors hereditary spherocytosis.
  • Ferritin — the single most useful follow-up test for a low MCHC; under 30 ng/mL confirms iron deficiency in most adults.
  • Reticulocyte count and bilirubin — raised when a high MCHC is due to hemolysis.
  • Peripheral blood smear — shows hypochromic cells, spherocytes, target cells or stippling and often settles the question in minutes.

What usually happens next

  1. Check whether hemoglobin, MCV and RDW on the same report are also abnormal. An isolated MCHC within a point of the reference range, with everything else normal, usually needs nothing more than a repeat with your next routine bloods.
  2. For a low MCHC, ask for ferritin (and CRP, since inflammation can hide a low ferritin). If ferritin is low, the next question is why: menstrual history, diet, gut symptoms, medications, and in men and post-menopausal women a look for gastrointestinal blood loss.
  3. For a low MCHC with normal ferritin, a high red cell count and a normal RDW, ask about family history and request hemoglobin electrophoresis to look for thalassemia trait before anyone prescribes iron.
  4. For a high MCHC, ask the lab to repeat on a fresh fasting sample and to review the blood film. If it is still high, a reticulocyte count, bilirubin, LDH, haptoglobin and a direct antiglobulin test look for hemolysis; a family history and an EMA-binding or osmotic fragility test look for spherocytosis.
  5. Recheck the CBC 8 to 12 weeks after any treatment starts. MCHC is one of the slowest indices to correct because it reflects the whole red cell population, which turns over in about 120 days.

Diet, lifestyle and natural levers with evidence

What can move MCHC once the cause is known. Nothing here replaces finding the cause.

Iron-rich foods paired with vitamin C

Strong evidence

Heme iron from red meat, poultry and fish is absorbed at 15 to 35 percent; non-heme iron from beans, lentils, tofu, spinach and fortified cereals at 2 to 20 percent. Adding 25 to 100 mg of vitamin C to a plant-based meal roughly doubles non-heme iron absorption in controlled feeding studies. This is the right first move for a mildly low MCHC with low ferritin and no ongoing blood loss.

Diet alone corrects mild deficiency slowly, over months; moderate or severe deficiency usually needs a supplement as well.

Oral iron, once the cause is known

Strong evidence

When ferritin confirms deficiency, 40 to 65 mg of elemental iron taken on alternate days raises hemoglobin and corrects MCHC in most people within two to three months. A 2017 Lancet Haematology trial found alternate-day dosing absorbed more total iron with fewer side effects than daily dosing, because each dose transiently raises hepcidin and blocks the next.

Do not take iron for a low MCHC until ferritin has been checked. Iron does nothing for thalassemia trait and is harmful in hemochromatosis and sideroblastic anemia, where stores are already high. Keep iron away from children.

Separating tea, coffee and calcium from iron-containing meals

Moderate evidence

Polyphenols in tea and coffee cut non-heme iron absorption by 60 to 90 percent when drunk with a meal, and calcium supplements of 300 mg or more cut it by roughly half. Leaving a one to two hour gap between these and iron-rich meals or tablets measurably improves absorption in human isotope studies.

Lactoferrin

Moderate evidence

Lactoferrin is an iron-binding milk protein. Randomized trials in pregnant women with iron-deficiency anemia found 100 mg of bovine lactoferrin twice daily raised hemoglobin about as well as 520 mg of ferrous sulfate, with fewer gut side effects, and a 2020 meta-analysis supported that finding. Evidence outside pregnancy is thinner.

Most trials used a specific saturated lactoferrin preparation; results may not transfer to every product.

Vitamin A alongside iron

Moderate evidence

Vitamin A helps release iron from stores and supports red cell production. In trials in children and pregnant women with low vitamin A status, combining vitamin A with iron raised hemoglobin more than iron alone. Benefit in well-nourished adults with normal vitamin A levels is unproven.

Avoid high-dose vitamin A supplements in pregnancy; food sources (liver, eggs, dairy, orange and dark green vegetables) are safe.

Treat the leak: heavy periods and gut loss

Strong evidence

In menstruating women, heavy periods are the most common reason iron deficiency keeps coming back. Reducing menstrual loss with tranexamic acid, a hormonal IUD or treating fibroids restores iron status in trials far more reliably than supplements alone. The same applies to treating celiac disease or an H. pylori infection, both of which block absorption.

When to see a clinician promptly

  • Hemoglobin below 10 g/dL on the same report, or below 7 to 8 g/dL at any time, which may need urgent treatment or transfusion.
  • Low MCHC with black, tarry or bloody stools, vomiting blood, or unexplained weight loss, which point to gastrointestinal bleeding.
  • Chest pain, breathlessness at rest, fainting or a racing heartbeat alongside any anemia.
  • High MCHC with jaundice, dark urine, fever or sudden fatigue, which suggests active hemolysis.
  • Any abnormal MCHC in a child, in pregnancy, or in a man or post-menopausal woman with iron deficiency, where the cause must be found rather than assumed.

Frequently asked questions

Is an MCHC of 36 or 37 bad?

Usually not. An MCHC of 36 sits at the top of most reference ranges and 37 is only slightly above it. If your hemoglobin, MCV and RDW are normal, this is most often lab variation or a mildly lipemic sample. Values of 38 or higher, or a high MCHC with a low hemoglobin, deserve a repeat and a blood film.

Is an MCHC of 30 or 31 bad?

It is mildly low and usually means the red cells are a little pale, most often from iron deficiency. It is not dangerous by itself. Ask for a ferritin level; if it is low, finding and fixing the cause of the iron loss corrects the MCHC over a few months. If ferritin is normal, thalassemia trait or chronic inflammation are the next possibilities.

Can dehydration raise MCHC?

Rarely, and only slightly. Dehydration concentrates the whole blood, so hemoglobin and hematocrit rise together and the ratio between them, which is MCHC, stays about the same. Only severe dehydration with high sodium, which pulls water out of the red cells themselves, nudges MCHC upward, and it corrects within hours of fluids.

What does high MCHC mean in cancer?

High MCHC is not a cancer marker. Cancers that affect the blood count, including lymphoma and leukemia, far more often lower hemoglobin and raise RDW than they raise MCHC. The exception is lymphoma or chronic lymphocytic leukemia that triggers an autoimmune hemolytic anemia with spherocytes, which can raise MCHC; in that case the hemoglobin is low and a Coombs test is positive.

What is the difference between MCH and MCHC?

MCH is the average amount of hemoglobin in one red cell, measured in picograms. MCHC is that amount divided by the cell's volume, a concentration in g/dL. A big cell with a normal concentration has a high MCH and a normal MCHC; a small cell with the same concentration has a low MCH and a normal MCHC. That is why MCH tracks MCV so closely, while MCHC changes only when the cell's hemoglobin content and its size move in different directions.

Can I raise my MCHC naturally?

If the cause is iron deficiency, yes: iron-rich foods with vitamin C, keeping tea and coffee away from meals, and treating whatever is draining iron will correct it over two to four months. If the cause is thalassemia trait, no diet or supplement changes it, and it needs no treatment. Have ferritin checked before starting iron, because excess iron is not harmless.

Why is my MCHC low but my hemoglobin normal?

This pattern often means early iron deficiency: the cells are starting to pale before the total hemoglobin has fallen below the reference range. It also occurs in thalassemia trait, where hemoglobin is often normal or only slightly low. A ferritin and a look at the red cell count and RDW separate the two.

Does a high MCHC mean I have spherocytosis?

Not on its own. Hereditary spherocytosis is the most common real cause of a persistently high MCHC, especially combined with a high RDW, but sample artefacts are far more common than the disease. If a repeat sample is still high, a blood film showing spherocytes, a family history, and an EMA-binding test confirm or exclude it.

References

  1. RBC indices. MedlinePlus Medical Encyclopedia, National Library of Medicine (2024)View source
  2. Complete blood count (CBC). Mayo Clinic (2023)View source
  3. Iron deficiency anemia. Mayo Clinic (2022)View source
  4. Van Vranken M. Evaluation of Microcytosis. American Family Physician (2010)View source
  5. Short MW, Domagalski JE. Iron Deficiency Anemia: Evaluation and Management. American Family Physician (2013)View source
  6. Hereditary Spherocytosis and Hereditary Elliptocytosis. Merck Manual Professional Version (2024)View source
  7. Evaluation of Anemia. Merck Manual Professional Version (2024)View source
  8. Iron: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements (2024)View source
  9. Michaels LA, Cohen AR, Zhao H, Raphael RI, Manno CS. Mean corpuscular hemoglobin concentration: a useful screening tool for hereditary spherocytosis. Journal of Pediatrics (1997)
  10. Zandecki M, Genevieve F, Gerard J, Godon A. Spurious counts and spurious results on haematology analysers: a review. Part II: white blood cells, red blood cells, haemoglobin, red cell indices and reticulocytes. International Journal of Laboratory Hematology (2007)
  11. Stoffel NU, Cercamondi CI, Brittenham G, et al.. Iron absorption from oral iron supplements given on consecutive versus alternate days and as single morning doses versus twice-daily split dosing in iron-depleted women. Lancet Haematology (2017)
  12. Iron-Deficiency Anemia. American Society of Hematology (2024)View source

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This page is educational and is not medical advice or a diagnosis. Lab results have to be interpreted together with your history, symptoms and other results by a clinician who knows you. Do not start or stop a supplement to change a lab value before the cause is known.