What does MCV stand for?

Mean corpuscular volume — the average size of your red blood cells. UK reports sometimes call it mean cell volume.

What is a normal MCV?

MedlinePlus gives 79 to 95 femtolitres as a common range, but labs vary. Use the range printed on your own report.

Can MCV be high or low without anemia?

Yes. MCV describes cell size, and your doctor reads it together with hemoglobin and your other results.

MCV

What does high or low MCV mean on a blood test?

MCV (mean corpuscular volume) is the average size of your red blood cells. A low MCV means the cells are smaller than usual and a high MCV means they are larger; doctors use it alongside hemoglobin and other results to work out the type and cause of anemia, if there is one.

Why it’s confusing

MCV is flagged on its own line, often with no explanation, and searching it brings up lists of conditions. But MCV mostly makes sense in combination: it is a clue to the type of red cell change, not a finding in itself.

It is reported in femtolitres (fL), a unit most people have never seen, which makes the number feel more technical than it is.

How to read it

MedlinePlus gives 79 to 95 femtolitres as a common normal range for MCV, but notes ranges vary slightly between labs — use the range on your report.

In general terms, MedlinePlus describes low MCV (smaller cells) as linked with microcytic anemia, which may be due to low iron levels, lead poisoning or thalassemia. High MCV (larger cells) is linked with macrocytic anemia, which may be due to low folate or vitamin B12 levels or chemotherapy, and with liver disease.

Read MCV next to hemoglobin: whether hemoglobin is low too, and whether other red cell indices (MCH, MCHC) are also outside their ranges. That combination is what your doctor looks at.

What it does not mean

That you have any of the conditions linked with it. Those are things a doctor may look into, not conclusions.
That an MCV just outside the range is significant on its own. Your doctor reads it with your other results.
That you should start iron or vitamin supplements because of it. Ask your doctor first.

Where you’ll see it

Complete blood count (CBC) or full blood count (FBC) reports, in the red cell indices.
Sometimes listed as “mean cell volume”.

Questions worth asking

Ask your doctor

Is my MCV result important alongside my other results?
Do I need any further tests?
Could any of my medicines affect this?

MCV flagged on your results? Attach the report or paste the text, and Clariti will explain it alongside the other lines.

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Common questions

What does MCV stand for?: Mean corpuscular volume — the average size of your red blood cells. UK reports sometimes call it mean cell volume.
What is a normal MCV?: MedlinePlus gives 79 to 95 femtolitres as a common range, but labs vary. Use the range printed on your own report.
Can MCV be high or low without anemia?: Yes. MCV describes cell size, and your doctor reads it together with hemoglobin and your other results.

Sources

Reading a scan report rather than a blood test or letter? Radily’s radiology report phrase guides explain the wording radiologists use.