Test Quick Guide
Mean corpuscular volume (MCV) is a measurement of the average size of red blood cells in a sample of blood. Red blood cells (RBC) carry oxygen throughout the body in order to support the health and function of organs and tissues.
An MCV test is part of a panel of tests called the red blood cell indices, which evaluate certain features of how red blood cells function. The MCV test can help to identify if red blood cells are too big or too small. Changes in red blood cell volume can affect how oxygen is distributed throughout the body and may be a sign of a blood disorder or other health conditions.
About the Test
The purpose of the mean corpuscular volume (MCV) test is to measure the average size of your red blood cells and check for signs of medical conditions such as anemia. Anemia is a common blood disorder in which your body is not able to carry and distribute a necessary amount of oxygen to organs and tissues.
An MCV test is performed along with several other measurements called red blood cell (RBC) indices. RBC indices provide information about the physical features of red blood cells and are included as part of a complete blood count (CBC), a routine blood test. The RBC indices include:
- Mean corpuscular volume (MCV)
- Mean corpuscular hemoglobin (MCH)
- Mean corpuscular hemoglobin concentration (MCHC)
- Red cell distribution width (RDW)
During an analysis of CBC, MCV may be compared to other red blood cell indices in order to diagnose different types of anemia, a condition in which blood does not carry enough oxygen to the body.
For more information about the purposes of a CBC, see our guide to the Complete Blood Count.
What does the test measure?
The mean corpuscular volume test measures the average size of your red blood cells.
Red blood cells can vary from normal in size to abnormally small or large. The average size is a calculation of the blood cells in a collected blood sample that describes the approximate size of red blood cells in your body.
When should I get the MCV test?
Mean corpuscular volume is one of the red blood cell indices, measured as part of a complete blood count test. A CBC is a standard laboratory test that is performed for many reasons. A CBC may be ordered during a routine health exam as well as part of diagnostic and follow-up testing for a wide range of conditions.
If you have symptoms of anemia, your health care provider will order a CBC and carefully compare the MCV to other tests, including other red blood cell indices.
Early signs and symptoms of anemia may include:
- Feeling weak or tired more often than usual
- Numbness and tingling in the hands and feet
- Loss of appetite
- Feeling irritable
- Problems concentrating or thinking
If the anemia progresses, additional signs and symptoms may include:
- Blue color to the whites of the eyes
- Desire to eat ice or other non-food items, including dirt
- Pale skin color
- Shortness of breath with mild activity or at rest
- Mouth ulcers
- Dizziness or lightheadedness when you stand up
- Sore or unusually red tongue
- Nails that break easily
- Abnormal or increased menstrual bleeding
Finding an MCV Test
How to get tested
MCV is included in a complete blood count (CBC) which is most commonly conducted in a healthcare setting by a licensed professional. A blood draw is generally required for a CBC.
If you have any concerns about your health and feel as though a mean corpuscular volume test might be right for you, contact your doctor.
Can I take the test at home?
Options are available for at-home complete blood count testing that include an assessment of MCV and other RBC indices. At-home CBC testing allows you to collect a sample of blood at home. That blood sample is then sent to a laboratory for analysis. It may take 2 to 3 days for the results to be available. You will be notified that results are ready to view through an online health portal or by email.
At-home CBC testing cannot be used to diagnose a disease or health condition. Rather, results should be shared with a health care provider who is familiar with your health history and current situation. Only a health care provider can interpret the values on a complete blood count for the purpose of assessing your health and diagnosing diseases. They may recommend repeating the CBC by traditional blood draw to confirm the results.
How much does the test cost?
The cost of a complete blood count, including MCV, depends on several factors, namely whether you are paying out of pocket or have health insurance. Because the CBC is commonly considered a routine test, the cost may be covered by insurance depending on your plan. However, there may still be charges related to copays and deductibles.
For specific details on expected costs for a complete blood count, talk to your doctor or insurance provider.
Taking the MCV Test
A blood sample is required for an MCV test as part of a complete blood count, which is ordered and conducted by a licensed health care professional. A blood sample is usually drawn from a vein inside the crook of your elbow or the top of your hand and collected in a test tube.
Before the test
There is usually no preparation required before carrying out a venous blood draw for a complete blood count in order to find the MCV unless your doctor considers it necessary.
Since the CBC is a common health assessment, it is possible that your health care provider may be drawing blood for other blood tests at the same time. Depending upon the purpose of your testing, your provider may ask you to not eat anything for a certain amount of time or give other instructions prior to your blood draw.
If there are any questions or concerns you have about any test preparation, contact your health care provider.
During the test
There are several steps that occur during a needle blood draw:
- In a health care setting, a licensed professional will locate the vein in your arm, hand or another part of your body from which they will draw blood.
- An alcohol wipe is used to clean the area of the arm where the needle will be inserted.
- A rubber band, called a tourniquet, is then placed around your upper arm to make the vein in your arm more visible and easier to access with a needle.
- The needle is placed in your vein, and a blood sample tube is then attached to the needle which automatically fills with blood. It is possible that you will feel a pinch or a little pain when the needle is inserted.
- After the sample vial is filled, the needle and tourniquet are removed.
After the test
Once the blood draw is over, a band-aid or cotton swab will be applied to the area where the needle went in to prevent bleeding. You may be instructed to keep this in place for an hour or more.
Slight dizziness, lightheadedness, and bruising are all common side effects after a blood draw. Less frequent side effects may include nausea, fainting, or persistent bleeding, among others.
If you feel lightheaded after your blood draw, your health care provider may ask you to stay seated briefly to monitor you and ensure you are able to safely walk and/or drive.
MCV Test Results
Receiving test results
The results of an MCV and CBC test may be available within a few minutes or up to a few days after the blood sample arrives at the laboratory, depending on where your sample was collected and the equipment and procedures that are used to conduct the test.
A report with the test results may be shared with you through an online health portal or you may request a physical copy. If the CBC test was ordered by your health care provider, a member of your health care team will likely contact you to discuss the results.
Interpreting test results
MCV test results are interpreted by comparing your MCV to a reference range, or the set of values that the laboratory expects for a healthy person. Reference ranges are based on the results of a large sample of healthy people and are associated with the equipment and procedures of the laboratory that conducts the test.
MCV is usually reported in femtoliters (fL). The American Board of Internal Medicine lists a typical MCV reference range as 80-98 fL.
MCV levels are reported as within the reference range if they fall within the expected range for a healthy individual. If the MCV result is outside of the reference range, it may be reported as high or low.
People with anemia or other health conditions can have normal or abnormal MCV results. It is also possible for healthy people to have a normal or abnormal MCV result.
In patients with anemia, MCV results are categorized as follows:
- Low MCV means that red blood cells are smaller than normal and may indicate microcytic anemia. This condition may be caused by iron deficiency, lead poisoning, or thalassemia, a genetic condition which causes your body to have less hemoglobin than normal.
- Normal MCV may indicate normocytic anemia. This can occur when an individual experiences symptoms of anemia due to sudden blood loss, kidney failure, or aplastic anemia, a rare disorder where the body does not produce enough red blood cells.
- High MCV means that red blood cells are too large and indicates macrocytic anemia. This condition can be caused by several factors including low folate or vitamin B12 levels or chemotherapy.
MCV is usually not interpreted as an isolated measurement. Rather, it is compared to the results of your other red blood cell indices and CBC values, like hemoglobin and hematocrit. Your doctor will also consider any symptoms or changes in your health when interpreting these test results.
Are test results accurate?
The mean corpuscular volume test is part of a complete blood count. The CBC is one of the most useful and common blood tests. It is generally accurate due to the modern laboratory methods and equipment used to analyze blood samples.
If your health care provider feels that the results don’t meet their expectations based on your other test results and overall health, they may order a follow-up test called a blood smear to manually analyze your blood sample.
The CBC is a comprehensive count of the cells in the blood and many factors can influence blood counts. It is possible to have abnormal MCV results on a CBC even when you are healthy and have no other signs of a developing health problem. It is also possible to have results within the reference range when you are experiencing symptoms or have a known condition or disease.
You can talk with your health care team to learn more about the accuracy and significance of your MCV results.
Do I need follow-up tests?
Since your blood affects every part of your body, many health conditions can cause changes in blood counts. Abnormal MCV test results may require additional follow-up testing. Additional blood, imaging, and other laboratory tests may all be considered based on the outcome of your initial MCV test.
Follow-up testing is also based on your symptoms, medical history, and the results of other tests. Your health care provider can explain what kind of follow-up testing is appropriate for your situation.
Questions for your doctor about test results
Your MCV levels may have some implications for your health. Some questions you may ask about your MCV results with your health care provider include:.
- What do my MCV levels indicate about my health?
- Can any diagnoses be made based on my MCV results?
- Do I need any follow-up tests based on my MCV results?
- If my MCV test results come back abnormal, is there anything you would suggest to improve my health?
MCV test vs. complete blood count (CBC)
MCV is a specific measurement of the average size of red blood cells found in a given blood sample. It is one of the red blood cell indices, which are a collection of measurements that evaluate certain qualities of red blood cells.
The CBC is a panel of blood tests that includes the red blood cell indices. The CBC allows your health care provider to get a snapshot of your overall health through analyzing the amount of cells in your blood including:
The CBC also provides information on other characteristics of your blood such as:
- Mean corpuscular hemoglobin (MCH)
- Mean corpuscular hemoglobin concentration (MCHC)
- Hematocrit (Hct)
- Hemoglobin (Hgb)
- Red cell distribution width (RDW)
MCV test vs. other red blood cell indices
Red blood cell indices are included in a complete blood cell count and provide information about qualities of your blood cells. MCV is the average size of red blood cells. The other RBC indices include the following measurements:
- MCH is the average amount of hemoglobin in a red blood cell.
- MCHC is the amount of hemoglobin in an individual red blood cell in relation to the size of the red blood cell.
- RDW is a measurement of the range of sizes of your red blood cells.
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