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URL of this page: https://medlineplus.gov/lab-tests/mcv-mean-corpuscular-volume/

MCV (Mean Corpuscular Volume)

What is an MCV Blood Test?

MCV stands for mean corpuscular volume. An MCV blood test measures the average size of your red blood cells.

Red blood cells carry oxygen from your lungs to every cell in your body. Your cells need oxygen to grow, reproduce, and stay healthy. If your red blood cells are too small or too large, it could be a sign of a blood disorder such as anemia, a lack of certain vitamins, or other medical conditions.

Other names: CBC with differential

What is it used for?

An MCV blood test is often part of a complete blood count (CBC). A CBC is a common blood test that measures many parts of your blood, including red blood cells. It is used to check your general health.

An MCV test may also be used with other tests to help diagnose or monitor certain blood disorders, including anemia. There are many types of anemia. An MCV test can help diagnose which type of anemia you have.

Why do I need an MCV blood test?

Your health care provider may order a complete blood count, which includes an MCV test, as part of your regular checkup. You may also have the test if you have a chronic (long-lasting) condition that could lead to anemia or if you have the symptoms of anemia:

What happens during an MCV blood test?

During the test, a health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

Will I need to do anything to prepare for the test?

You don't need any special preparations for an MCV blood test. If your provider has ordered more tests on your blood sample, you may need to fast (not eat or drink) for several hours before the test. Your provider will let you know if there are any special instructions to follow.

Are there any risks to the test?

There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

What do the results mean?

An MCV test alone cannot diagnose any disease. Your provider will use the results of your MCV, other test results, and your medical history to make a diagnosis.

If your results show that your red blood cells are smaller than normal, it may be a sign of:

  • Certain types of anemia, including iron-deficiency anemia, the most common type
  • Thalassemia, an uncommon genetic condition

If your results show that your red blood cells are larger than normal, it may be a sign of:

It's also possible to have anemia with a normal MCV. This may happen if anemia is caused by conditions, such as:

If your MCV levels are not in the normal range, it doesn't always mean that you have a medical problem that needs treatment. Diet, activity level, medicines, a menstrual period, and other conditions can affect the test results. Talk with your health care provider to learn what your results mean.

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about an MCV blood test?

If your provider thinks you may have anemia or another blood disorder, you may have other red blood cell tests with an MCV. These tests may include a red blood cell count and measurements of hemoglobin. All together, these tests are called red blood cell indices.

References

  1. American Society of Hematology [Internet]. Washington D.C.: American Society of Hematology; c2022. Anemia [cited 2022 Mar 19]; [about 4 screens]. Available from: https://www.hematology.org/education/patients/anemia
  2. Hinkle J, Cheever K. Brunner & Suddarth's Handbook of Laboratory and Diagnostic Tests. 2nd Ed, Kindle. Philadelphia: Wolters Kluwer Health, Lippincott Williams & Wilkins; c2014. Red Cell Indices; 451 p.
  3. Maner BS, Moosavi L. Mean Corpuscular Volume. [Updated 2021 Jul 10; cited 2022 Mar 19]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK545275/
  4. National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; How Are Thalessemias Diagnosed? [updated 2012 Jul 3; cited 2017 Mar 28]; [about 7 screens]. Available from: https://www.nhlbi.nih.gov/health/health-topics/topics/thalassemia/diagnosis
  5. National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Blood Tests; [ cited 2022 Mar 19]; [about 16 screens]. Available from: https://www.nhlbi.nih.gov/health-topics/blood-tests
  6. National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Iron Deficiency Anemia; [cited 2022 Mar 19]; [about 28 screens]. Available from: https://www.nhlbi.nih.gov/health-topics/iron-deficiency-anemia
  7. Testing.com [Internet]. Seattle (WA): OneCare Media; c2022. Anemia; [modified 2021 Nov 9; cited 2022 Mar 119]; [about 10 screens]. Available from: https://www.testing.com/anemia-testing/
  8. Testing.com [Internet]. Seattle (WA): OneCare Media; c2022. Complete Blood Count (CBC); [modified 2021 Dec 2; cited 2022 Mar 19]; [about 22 screens]. Available from: https://labtestsonline.org/understanding/analytes/cbc/tab/test
  9. Testing.com [Internet]. Seattle (WA): OneCare Media; c2022. MCV Test; [modified 2022 Jan 7; cited 2022 Mar 19]; [about 10 screens]. Available from: https://www.testing.com/tests/mcv-test/
  10. University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2022. Health Encyclopedia: Complete Blood Count with Differential [cited 2022 Mar 19]; [about 4 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=complete_blood_count_w_differential
  11. Yang, J., Yan, B., Yang, L. et al. Macrocytic anemia is associated with the severity of liver impairment in patients with hepatitis B virus-related decompensated cirrhosis: a retrospective cross-sectional study. BMC Gastroenterol [Internet]. 2018 Nov 1 [cited 2022 Mar 19]; 18, 161. Available from: https://doi.org/10.1186/s12876-018-0893-9

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.