MCV (Mean Corpuscular Volume): MedlinePlus Lab Test Information

T What is an MCV Blood Test?
P MCV stands for mean corpuscular volume. There are three main types of corpuscles (blood cells) in your blood–red blood cells, white blood cells, and platelets. An MCV blood test measures the average size of your red blood cells, also known as erythrocytes. Red blood cells move 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 vitamin deficiency, or other medical condition.
P Other names: CBC with differential

T What is it used for?
P An MCV blood test is often part of a complete blood count (CBC), a routine screening test that measures many different components of your blood, including red cells. It may also be used to diagnose or monitor certain blood disorders.

T Why do I need an MCV blood test?
P Your health care provider may have ordered a complete blood count, which includes an MCV test, as part of your regular checkup or if you have symptoms of a blood disorder. These symptoms include:
- Fatigue
- Unusual bleeding or bruising
- Cold hands and feet
- Pale skin

T What happens during an MCV blood test?
P 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.

T Will I need to do anything to prepare for the test?
P You don't need any special preparations for an MCV blood test. If your health care 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 health care provider will let you know if there are any special instructions to follow.

T Are there any risks to the test?
P 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.

T What do the results mean?
P If your results show that your red blood cells are smaller than normal, it may indicate:
- Iron-deficiency anemia or other types of anemia
- Anemia is a condition in which your blood has a lower than normal amount of red blood cells. Iron-deficiency anemia is the most common form of anemia.
- Thalassemia, an inherited disease that can cause severe anemia
P If your results show that your red blood cells are larger than normal, it may indicate:
- A vitamin B12 deficiency
- A deficiency in folic acid, another type of B vitamin
- Liver disease
- Hypothyroidism
P If your MCV levels are not in the normal range, it doesn't necessarily mean that you have a medical problem needing treatment. Diet, activity level, medicines, a women's menstrual cycle, and other considerations can affect the results. Talk to your health care provider to learn what your results mean.

T Is there anything else I need to know about an MCV blood test?
P If your health care provider suspects you have anemia or another blood disorder, he or she may order additional tests of your red blood cells. These include a red blood cell count and measurements of hemoglobin.

T References
- American Society of Hematology [Internet]. Washington D.C.: American Society of Hematology; c2017. Anemia [cited 2017 Mar 28]; [about 3 screens]. Available from: http://www.hematology.org/Patients/Anemia
- Bawane V, Chavan RJ. Effect of Low Count of Leukocytes In The Rural People. International Journal of Innovative Research & Development [Internet]. 2013 Oct [cited 2017 Mar 28]; 10(2):111–16. Available from: http://www.ijird.com/index.php/ijird/article/download/39419/31539
- 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.
- Lab Tests Online [Internet]. Washington D.C.: American Association for Clinical Chemistry; c2001–2017. Anemia [updated 2016 Jun 18; cited 2017 Mar 28]; [about 2 screens]. Available from: https://labtestsonline.org/understanding/conditions/anemia/start/4
- Lab Tests Online [Internet]. Washington D.C.: American Association for Clinical Chemistry; c2001–2017. Complete Blood Count: The Test [updated 2015 Jun 25; cited 2017 Mar 28]; [about 4 screens]. Available from: https://labtestsonline.org/understanding/analytes/cbc/tab/test
- Lab Tests Online [Internet]. Washington D.C.: American Association for Clinical Chemistry; c2001–2017. Complete Blood Count: The Test Sample [updated 2015 Jun 25; cited 2017 Mar 28]; [about 3 screens]. Available from: https://labtestsonline.org/understanding/analytes/cbc/tab/sample
- 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
- National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; How is Anemia Diagnosed? [updated 2012 May 18; cited 2017 Mar 28]; [about 7 screens]. Available from: https://www.nhlbi.nih.gov/health/health-topics/topics/anemia/diagnosis
- National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Types of Blood Tests [updated 2012 Jan 6; cited 2017 Mar 28]; [about 2 screens]. Available from: https://www.nhlbi.nih.gov/health/health-topics/topics/bdt/types
- National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; What Are Thalessemias? [updated 2012 Jul 3; cited 2017 Mar 28]; [about 3 screens]. Available from: https://www.nhlbi.nih.gov/health/health-topics/topics/thalassemia
- National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; What Are the Risks of Blood Tests? [updated 2012 Jan 6; cited 2017 Mar 28]; [about 5 screens]. Available from: https://www.nhlbi.nih.gov/health/health-topics/topics/bdt/risks
- National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; What is Iron Deficiency Anemia? [updated 2014 Mar 16; cited 2017 Mar 28]; [about 2 screens]. Available from: https://www.nhlbi.nih.gov/health-topics/topics/ida
- National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; What Do Blood Tests Show? [updated 2012 Jan 6; cited 2017 Mar 28]; [about 6 screens]. Available from: http://www.nhlbi.nih.gov/health/health-topics/topics/bdt/show
- National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; What To Expect with Blood Tests [updated 2012 Jan 6; cited 2017 Mar 28; [about 4 screens]. Available from: https://www.nhlbi.nih.gov/health/health-topics/topics/bdt/with
- University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2017. Health Encyclopedia: Complete Blood Count with Differential [cited 2017 Mar 28]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=167&ContentID=complete_blood_count_w_differentia

