Doctor's Assessment Included
Every result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.
MCV value: what the MCV of your blood tells you
MCV (Mean Corpuscular Volume) measures the average size of your red blood cells. The MCV of blood is a useful indicator for classifying different types of anemia. Red blood cells carry oxygen around the body, so their size can offer insight into the cause of blood-related conditions.
Reference Ranges
Reference ranges may vary between laboratories. When you order a test, a BIG-registered doctor assesses your personal results in context. For treatment decisions, discuss your results with your GP.
What It Measures
This test works out the average volume of a single red blood cell. The volume of a single red blood cell is measured in femtolitres (fL). The value is derived from your hematocrit and your red blood cell count.
MCV reflects the average size of your red blood cells. It helps sort your red blood cells into smaller than normal, normal, or larger than normal. That makes the MCV value a useful starting point when looking into the cause of anaemia.
Why It Matters
MCV helps work out which type of anaemia is present. A low MCV value can point to iron deficiency, while a high MCV value may relate to a shortage of vitamin B12 or folate. Common causes of low MCV include iron deficiency anemia, the most common cause, and blood loss over time. A high value means your red blood cells are larger than normal. It can be linked to liver problems or certain medications. A doctor reviews the result alongside your other blood values.
When to Test
MCV is a standard component of a complete blood count, so it is often measured automatically. It is particularly useful when symptoms consistent with anaemia are present: fatigue, pallor, dizziness, shortness of breath, or difficulty concentrating.
If you already know you have anaemia, MCV helps identify the cause and guide appropriate treatment. With a known deficiency in iron, vitamin B12, or folate, repeated MCV measurements can show whether supplementation is having an effect.
MCV is also regularly measured in cases of prolonged excessive alcohol use, as it is one of the most sensitive markers for alcohol-related liver damage. Fasting is not required for MCV.
Symptoms
Low Levels
High Levels
Lifestyle Tips
For low MCV due to iron deficiency, diet is an important factor. Iron-rich foods — red meat, legumes, dark leafy greens, and whole grains — help replenish your iron stores. Combine plant-based iron with vitamin C (bell peppers, citrus fruits) for better absorption. Tea and coffee with meals actually inhibit iron absorption.
For high MCV due to vitamin B12 deficiency, consider more animal products (meat, fish, eggs, dairy) or targeted supplementation. Vegans always need a B12 supplement. Folate is found particularly in green leafy vegetables, legumes, and citrus fruits.
If alcohol use is the cause of high MCV, reducing or stopping is the only effective measure. MCV typically normalises within two to four months after cessation.