What is MCH?
A red blood cell is essentially a bag of haemoglobin, and MCH is how much sits on average in each bag: the total haemoglobin in your blood divided by the number of red cells. It is a calculated value that says something about production. If there was enough iron while the cell was being made, it is well filled; if there was too little, it enters the blood pale and light. If there was too little B12 or folate, the cell has grown too large and takes proportionally more haemoglobin with it. So MCH almost always runs in step with MCV, the cell size: small cells are also pale cells, large cells are also heavily filled cells. The two tell the same story, and MCH is often the more sensitive of the two, because in an iron deficiency the filling drops slightly earlier than the volume. Like MCV it is an average over cells that last four months, so it moves slowly. Your report shows MCH in fmol or in amol; internationally in picograms, which gives very different figures. Normal is about 1.70 to 2.10 fmol per cell. There is not always a band beside it, because MCV usually says the same already.
Why is MCH relevant?
MCH is the value that shows whether your red cells are well filled, and with iron that is the heart of the matter. An iron deficiency makes cells that are paler, and MCH therefore often drops just slightly earlier than MCV and well before haemoglobin goes below the limit. An MCH at the low end with a ferritin at the low end is a deficiency already working through into production, even when the blood count is otherwise still called normal. For anyone who menstruates, eats plant-based or exercises a lot, that is an early signal. The second reason is that MCH shows whether topping up is working. After starting iron, the marrow makes better-filled cells within days, and in the weeks after MCH creeps up while the old, pale cells are broken down. That makes it a good measure to follow whether the iron tablet does what it should, together with the reticulocytes and the haemoglobin. At the high end MCH tells the same as MCV: a deficiency of B12 or folate, or alcohol. And with small, pale cells and a normal ferritin, together with a high cell count it points at thalassaemia trait, which is not a disease but good to know.
MCH reference ranges
What counts beside the number:
- MCV and MCHC, which almost always point the same way; if they diverge, the picture is mixed
- Haemoglobin, because a low MCH with a normal haemoglobin is a deficiency in production not yet in the transport
- Ferritin with a low value: low in iron deficiency, normal in thalassaemia
- Vitamin B12, folate and TSH with a high value
- RDW, which shows a change earlier than the average
- The unit on your report: fmol, amol or picograms
Not every lab prints a band for MCH, because MCV almost always points the same way. Mind the unit: Dutch labs report in fmol or amol, international sources in picograms, and those figures are not interchangeable. It is an average over cells that last four months, so it moves slowly. Always read MCH beside MCV, haemoglobin and ferritin.
MCH = haemoglobin divided by the red cell count
fmol
÷ =
What Dutch labs actually use
1.70 – 2.10fmol
At Certe this is normal.
every lab calls 1.70 – 2.10 fmol normal. Outside that range every lab calls it abnormal.
Every age, per lab
| Laboratory | Group | Reference range |
|---|---|---|
| Certe2026 | Men from 18 yrs | 1.70–2.10 fmolconverted |
| Women from 18 yrs | 1.70–2.10 fmolconverted |
Each band as the lab publishes it, retrieved in 2026, unless marked otherwise.
MCH high or low: what it means
A low MCH means pale, poorly filled cells. In order of how often it occurs: an iron deficiency, thalassaemia trait, and rarely a chronic disease. Ferritin tells the difference: low in iron deficiency, normal in thalassaemia. A low MCH with a normal haemoglobin is a deficiency that already sits in production but not yet in the transport. A high MCH means large, heavily filled cells. In order: a deficiency of vitamin B12 or folate, alcohol, and an underactive thyroid. B12, folate and TSH you settle with a draw; alcohol you settle yourself. MCH and MCV should sit high together here; if they do not, the picture is mixed and RDW says more. What you do about it: with a low MCH from iron deficiency you refill the store, with red meat, fish, legumes and green vegetables with vitamin C, and where needed an iron tablet every other day; MCH creeps up in the weeks after. With a high MCH you top up B12 or folate or cut down on alcohol, and it falls in the months after. Always read MCH beside MCV, MCHC, haemoglobin and RDW, and beyond that beside ferritin with a low value and B12 and folate with a high one. Mind the unit, because fmol, amol and picograms give very different figures.
What lowers it
Cells that enter the blood pale and light because there was too little iron to fill them.
| Cause | How often |
|---|---|
| Iron deficiencyWithout enough iron every new cell gets less haemoglobin; MCH drops just slightly earlier than MCV, and ferritin is then low | Often |
| Thalassaemia traitSmall, pale cells in a high number, with a normal ferritin; inherited, not a disease, and iron does not help | Sometimes |
| Chronic diseaseA long-standing inflammation holds on to iron; the cells sometimes become slightly paler, usually they stay normal | Rare |
What raises it
Cells that are large and heavily filled because the division faltered.
| Cause | How often |
|---|---|
| Vitamin B12 or folate deficiencyThe cell keeps growing while the division falters and takes proportionally more haemoglobin with it; MCV sits high with it | Often |
| AlcoholDisturbs production in the marrow and makes larger, more heavily filled cells; with a normal B12 and folate the most common reason | Sometimes |
| Thyroid problemsAn underactive thyroid slows production and makes the cells somewhat larger; TSH shows it | Sometimes |
How does a MCH blood test work?
- Referral
- Not needed. MCH is in every blood count you can have measured yourself.
- Fasting
- Not needed. MCH does not move with food or with your fluid balance.
- When
- At any time; the value changes over weeks to months, not over days.
- The draw
- One tube of blood from a vein in your arm, the same tube as for the rest of your blood count; MCH is calculated from haemoglobin and the red cell count.
- Repeating
- A month after starting iron to see whether the new cells are better filled, and after three to four months for the full picture.
- Which test
- MCH is in the Iron & fatigue test (€99) and in .
- Where to draw
- You can draw at 250+ locations near you, no referral needed. See the locations
Frequently asked questions
What is MCH?
The average amount of haemoglobin per red blood cell: your haemoglobin divided by your red cell count. Where MCV says how large your cells are, MCH says how much oxygen carrier sits in them on average. The two almost always move together, because small cells are also pale cells and large cells are also heavily filled cells.
What is a normal MCH level?
About 1.70 to 2.10 fmol per red blood cell. Not every lab prints a band for it, because MCV usually says the same already. Mind the unit: fmol, amol and picograms give very different figures, and you only compare within the same unit.
What does a low MCH mean?
Pale, poorly filled cells. Usually an iron deficiency: without enough iron every new cell gets less haemoglobin, and MCH drops just slightly earlier than MCV and well before haemoglobin goes below the limit. The other explanation is thalassaemia trait, with small, pale cells and a normal ferritin. Ferritin tells the two apart.
What does a high MCH mean?
Large, heavily filled cells. A deficiency of vitamin B12 or folate lets the cell keep growing while the division falters, and alcohol does the same. An underactive thyroid also makes the cells somewhat larger. MCV then sits high with it, and B12, folate and TSH from the same draw say which it is; with a normal B12 and folate it is usually alcohol.
Why do MCH and MCV move together?
Because they both describe how a cell was made. If there was too little iron, the cell is small and pale; if there was too little B12 or folate, it is large and heavily filled. If they diverge, the picture is mixed, for instance a deficiency of iron and B12 at the same time, and then RDW, the spread in cell size, says more than the two averages.
How does MCH show whether topping up iron works?
After starting iron the marrow makes better-filled cells within days, and in the weeks after MCH creeps up while the old, pale cells are broken down. Together with the reticulocytes, which rise within a week, and the haemoglobin, which should be clearly higher after a month, it shows that the tablet does what it should.
What is the difference from MCHC?
MCH is the amount of haemoglobin per cell; MCHC is that same amount divided by the cell volume, so how densely the haemoglobin is packed in the cell. In an iron deficiency both fall; in a B12 deficiency MCH rises while MCHC stays normal, because the larger cell is proportionally just as full. MCH is the more sensitive of the two.
Do I need to fast for an MCH test?
No. MCH does not move with food or with your fluid balance, and it comes from the same tube as your whole blood count, so MCV, haemoglobin and RDW sit beside it automatically.
Which tests include MCH?
MCH is in the Iron & fatigue test (€99, also as an add-on for €15), in the Biological age test (€69, also as an add-on for €15), in the comprehensive test (€229) and in .
Related biomarkers
Read on
Sources
- 1.NHG guideline on anaemia (M76), Dutch College of General Practitioners. 2024. richtlijnen.nhg.org
- 2.Certe, test catalogue (Dutch): MCH. 2026. bepalingenwijzer.certe.nl
Educational information only, not medical advice. Consult a healthcare professional for clinical decisions.
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