BloodTestEasy

MCV 67 fL

Markedly low (severe microcytosis)

Consider discussing this with your doctor in the coming weeks.

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  • Markedly low (severe microcytosis)
  • Low (microcytosis)
  • Borderline low
  • Normal
  • Borderline high (mild macrocytosis)
  • High (macrocytosis)
  • Markedly high (severe macrocytosis)
Your band
Markedly low (severe microcytosis) · 6–7 fL
Distance from typical range
13 fL below 80

What 67 fL means

An MCV of 67 fL is well below the typical adult range of 80–100 fL, meaning your red blood cells are much smaller than average.

Red cells this small almost always have a specific, findable cause — most often long-standing iron deficiency or an inherited hemoglobin trait such as thalassemia. Thalassemia trait can produce MCVs in the 60s in people who feel completely well and are not truly ill, while iron deficiency severe enough to do this usually comes with a low hemoglobin as well. The rest of your CBC (hemoglobin, red cell count, RDW) helps tell these two apart, and iron studies usually settle it.

Most US labs consider roughly 80 to 100 fL a normal adult MCV for both men and women, following the convention used by StatPearls and most US laboratories; exact cutoffs vary slightly by laboratory.

Common causes

  • Long-standing iron deficiency, often from slow blood loss (heavy periods, ulcers, colon polyps)
  • Thalassemia trait or thalassemia (alpha or beta), an inherited condition
  • Poor iron absorption (celiac disease, prior stomach or bariatric surgery)
  • Very low dietary iron over a long period
  • Other inherited hemoglobin variants, such as hemoglobin E trait
  • Lead exposure or sideroblastic anemia (both rare)

Symptoms that can go with it

  • Fatigue or low energy
  • Shortness of breath with activity
  • Pale skin
  • Brittle nails or spoon-shaped nails
  • Cravings for ice, dirt, or starch (pica)
  • Restless legs, especially at night
  • Cold hands and feet
  • No symptoms at all is common with thalassemia trait

Sensible next steps

  1. If you are currently passing black, tarry, or bloody stools, or you have chest pain, severe shortness of breath, dizziness, or fainting, seek same-day medical care rather than waiting for an appointment — these can signal active bleeding or significant anemia.
  2. Arrange to see your clinician within the next week or two — a value this low deserves a clear diagnosis, not a wait-and-see approach
  3. Ask about iron studies (ferritin, iron, TIBC) and, if iron is normal, hemoglobin electrophoresis to check for thalassemia trait
  4. Mention any bleeding: heavy periods, black or bloody stools, or frequent blood donation
  5. Do not start iron supplements on your own — iron will not help thalassemia and taking it before testing can muddy the diagnosis
  6. If iron deficiency is confirmed, discuss with your clinician whether the source of blood loss needs to be investigated

Frequently asked questions

Is 67 fL a normal MCV level?

No — 67 fL is well below the typical 80–100 fL range. Values in the 60s usually mean long-standing iron deficiency or an inherited trait like thalassemia, and deserve a proper workup within the next week or two.

What does a low MCV mean?

At 67 fL, the microcytosis is marked. This level is typical of significant, long-standing iron deficiency or thalassemia trait. Iron studies plus, if needed, hemoglobin electrophoresis will identify which — and if it is iron deficiency, finding the source of blood loss matters as much as replacing the iron.

What does a high MCV mean?

A high MCV (macrocytosis) means your red blood cells are larger than normal. Common causes include vitamin B12 or folate deficiency, regular alcohol use, liver disease, an underactive thyroid, and several medications. Mild elevations are often benign, but a persistently or clearly high MCV deserves a workup — mainly to rule out B12 deficiency, which can affect nerves if untreated.

Can my MCV be abnormal even if I'm not anemic?

Yes. MCV describes red cell size, not red cell quantity, so it can drift out of range while your hemoglobin is still normal. A low MCV without anemia is common in thalassemia trait and early iron deficiency; a high MCV without anemia often comes from alcohol, medications, or early B12/folate shortfall. An abnormal MCV with normal hemoglobin is often an early clue worth a simple follow-up rather than a cause for alarm.

Does drinking alcohol raise MCV?

Yes — regular alcohol use is one of the most common causes of a mildly elevated MCV, even without anemia and even before the liver shows any trouble. The effect comes both from alcohol's direct action on the bone marrow and from the folate deficiency that can accompany heavy drinking. The MCV typically drifts back toward normal over two to four months after cutting back, since that is how long it takes to replace the red cell population.

Should I worry about an MCV of 67 fL?

Take it seriously but calmly: 67 fL is markedly low and almost always has a specific cause — most often long-standing iron deficiency or thalassemia trait. Arrange evaluation within a week or two rather than waiting months.

Check a different MCV value

Related values on your lab report

Sources

Educational information, not medical advice. Reference ranges vary between labs — always compare with the range printed on your own report and discuss results with your doctor. Full disclaimer