MCV, or Mean Corpuscular Volume, is a hematometric index present in the blood count that indicates the average size of red blood cells, which are red blood cells.
Changes in the MCV value may be a sign of anemia, hemorrhage, hypothyroidism, thalassemia or chronic infections, for example.
Knowing the amount of MCV is particularly important to help diagnose anemia and to monitor the patient after starting treatment. However, MCV analysis must be done together with the analysis of the entire blood count, mainly HCM, RDW and hemoglobin. Learn how to interpret the blood count.
VCM Reference Value
The normal VCM value is between 80 and 100 fl, which may vary according to the laboratory. To find out if your MCV is normal, enter your test results into the following calculator:
Possible VCM changes
The main changes to VCM are:
VCM alto
A high MCV indicates that the red blood cells are large, which may be a sign of:
- Megaloblastic anemia;
- Pernicious anemia;
- Alcohol dependence;
- Hemorrhages;
- Myelodysplastic syndrome;
- Hypothyroidism.
In case of high MCV, it is also common to observe an increase in RDW, which is a blood count index that evaluates the difference in size between red blood cells. Find out what the RDW means in the blood test.
low MCV
Low MCV indicates that the red blood cells present in the blood are small, being called microcytic, and may occur in the case of:
- Iron deficiency anemia;
- Thalassemia minor;
- Congenital spherocytosis;
- Uremia;
- Chronic infections.
In the case of iron deficiency anemia, for example, it is also common to observe changes in the HCM value, which assesses the concentration of hemoglobin per red blood cell. Understand what HCM is.
VCM in the diagnosis of anemia
For the laboratory diagnosis of anemia, the doctor mainly checks the hemoglobin values, in addition to other indices, such as MCV and HCM. If hemoglobin is low, the type of anemia can be identified based on the following results:
- Low VCM and HCM: Means microcytic anemia, such as iron deficiency anemia;
- Normal VCM and HCM: Means normocytic anemia, which may be indicative of thalassemia;
- high MCV: Means macrocytic anemia, such as megaloblastic anemia, for example.
Based on the results of the blood count, the doctor may order other tests that can confirm the diagnosis of anemia. See which tests confirm anemia.
