What is mcv in cbc blood test

Mean corpuscular volume MCV measures the size of your red blood cells. It can be used to help diagnose blood disorders, such as anemia.

Keep reading to learn more about the causes of low and high MCV and how to address them. Mean corpuscular volume MCV is the average size volume of the red blood cells in your body. It is normally measured as part of a complete blood count , which measures your hemoglobin , hematocrit , and red blood cell levels [ 1 ].

Along with the red cell distribution width RDW test, MCV is used to diagnose many diseases, including anemia, thalassemia , liver disease, and iron deficiency [ 1 ]. The normal range of MCV is around 80 — 94 fl [ 1 ]. However, what your labs report as a normal range may differ slightly. Some lab-to-lab variability can happen due to differences in equipment, techniques, and chemicals used.

There are anemias in which red blood cell size is normal normocytic anemia [ 2 ]. Your doctor will interpret your results in conjunction with your medical history and other test results. An MCV below normal means that your red blood cells are smaller than normal microcytic. Microcytosis is usually a result of the inability to form hemoglobin, which is a protein that is responsible for transporting oxygen in the blood [ 1 , 3 ].

However, a result that is slightly lower may not be of medical significance, as this test often varies from day to day and from person to person. Your doctor will interpret this result, taking into account your medical history and other tests, such as RBC, hemoglobin, and other red blood cell indices.

Microcytosis patients usually do not show any symptoms, unless their anemia is severe. Other complete blood count tests can help determine the cause of microcytosis, such as RDW and iron markers [ 4 ]. Causes shown below are commonly associated with low MCV. Work with your doctor or other health care professional to get an accurate diagnosis of the underlying cause. The most common cause of low MCV is iron deficiency anemia.

Without enough iron in the body, red blood cells cannot make hemoglobin, and this results in a smaller red blood cell size [ 3 , 5 ]. In a study of patients, the main cause of their low MCV microcytosis was iron deficiency.

In addition, MCV in the study correlated with the severity of the underlying iron deficiency [ 6 ]. Iron deficiency can be due to dietary causes, or conditions that impair nutrient absorption such as celiac disease.

Anemia of chronic disease is the most common cause of anemia after iron deficiency anemia. This type of anemia has been associated with smaller red blood cells and low MCV [ 5 ]. While the doctor is taking the blood sample, a person may feel a little pain and a stinging sensation. Drawing blood carries few risks. However, everyone is different, and sometimes blood collection is more straightforward in some people than in others. These symptoms indicate conditions that affect the size of red blood cells, making them smaller or larger than usual.

When red blood cells are smaller than expected, a person likely has microcytic anemia. If they are larger, a person may have macrocytic anemia. A typical adult MCV level is 80— femtoliters fl. Specific levels for different ages and sexes include:.

MCV results may differ among labs, so people should not worry if their reading is slightly above or below these ranges. When a person has an MCV level below 80 fl , this suggests they have microcytic anemia.

Microcytic anemia is a type of anemia in which red blood cells are smaller than usual. Iron deficiency causes microcytic anemia. A person usually develops an iron deficiency due to an underlying health condition or factors such as diet and medications.

Thalassemia is a condition where the body does not make enough normal hemoglobin. It is a genetic condition that a person inherits from their parents. Thalassemia can range from mild to severe. If a person has mild thalassemia, they may have mild anemia or not present with any signs or symptoms. If someone has severe thalassemia, they may require regular red blood cell transfusions.

If someone has a high MCV level, their red blood cells are larger than usual, and they have macrocytic anemia. Macrocytosis occurs in people with an MCV level higher than fl. Megaloblastic anemia is a type of macrocytic anemia.

Deficiencies in cobalamin vitamin B12 and folate vitamin B9 are the most common causes of megaloblastic anemia. Vitamin B12 deficiency may occur when following a vegan diet. This is because vitamin B12 naturally occurs in animal sources.

A person can take vitamin B12 supplements or consume vitamin Bfortified foods to alleviate symptoms. This is an inflammatory condition that affects the stomach, particularly the parietal cells that make intrinsic factor. In a hospital or clinic with a lab, results might be available the same day. When looking at your results, it's helpful for your healthcare provider to compare them to your prior CBCs. That way, they can see if your MCV has changed over time.

Most often, a healthcare provider wants to look at MCV if you have anemia so that they can determine which type you have. But it is also important even if you don't have anemia. Several things can cause a high or low MCV. But your healthcare provider should always interpret the MCV alongside other measurements when looking for the cause of anemia. A normal MCV is 80 to 96 femtoliters per cell. A femtoliter is a cubic micrometer. Unusually high or low MCV can indicate several conditions.

In addition to anemia, MCV outside of an expected range can indicate poisoning, vitamin deficiency, and liver disease. A low MCV may be seen with:. The lowest MCV levels for example, less than 70, called severe microcytosis are usually a sign of iron deficiency anemia or thalassemia. However, conditions don't always fall neatly into these categories. Iron deficiency anemia may sometimes have a normal MCV.

MCV typically increases with age. Conditions associated with a high MCV include:. The highest MCV levels for example, higher than , known as severe macrocytosis are usually due to vitamin B12 or folate deficiencies or cold agglutinin disease. Anemias that often have a normal MCV normocytic anemias include:. When anemia is present, MCV can help determine the causes.

The reticulocyte count a measure of new red blood cells is an important first step in determining the cause of anemia. That's because it can separate anemias into two major categories:. A normal or low reticulocyte count suggests that the body cannot keep up with making new red cells.

For example, this may happen when someone is deficient in iron or folate. However, on the other hand, a high count indicates the body is trying to raise the low red blood cell count.

This is seen when red blood cells are lost from bleeding or cell damage. Cells with a low MCHC are called hypochromic , which means light-colored. RDW describes the variation in the size of red blood cells.

Anisocytosis is the medical term for red blood cells of various sizes. For example, in sideroblastic anemia, most cells may be large, but some cells will be small. Further tests may be helpful in combination with MCV and other red blood cell indices as well.

They include:. Blood differential : A blood differential may give further clues about anemia. This test shows variations in cell size, shape, or color. Other findings may include:. Iron tests : Serum iron, iron-binding capacity, and serum ferritin can be helpful, especially with a low MCV. For example, the MCV will be low with sideroblastic anemia, but iron stores may be very high. Vitamin B12 level : Vitamin B12 levels can be used to diagnose deficiency in macrocytic anemias.

Hemoglobin electrophoresis HE : HE can test for a beta-thalassemia trait an inherited blood disorder. It can not, however, test for alpha thalassemia an inherited anemia. Bone marrow biopsy: A bone marrow biopsy may be helpful to look at the number and types of cells in the biopsy.

It may also be used to evaluate iron. MCV, along with other tests, can help your healthcare provider determine what type of anemia you have. In some cases, a bone marrow biopsy may also be helpful. The MCV test can provide important information even when the red blood count is normal. A few examples include:. For example, a study found that people with kidney disease who had a high MCV were more than twice as likely to die of all causes of mortality. In addition, they were over 3.

Follow-up testing depends on the results of the MCV test and other measurements. MCV is useful for evaluating anemia and some other medical conditions. But it is not usually looked at alone. In addition to anemia, MCV outside of an expected range can suggest poisoning, vitamin deficiency, and liver disease.

MCV can also help determine a prognosis for certain cancers and chronic kidney disease. In addition, it may be used as a tool to evaluate cognitive function in older adults. The MCV test, especially when combined with other numbers on a CBC, can help diagnose anemia, planning treatment, or predicting prognosis with other medical conditions.

Unfortunately, these small numbers on a CBC can easily be overlooked. So it's a good idea to be your own advocate and ask your healthcare provider about any levels that are marked as abnormal. A high mean corpuscular volume MCV in a blood test indicates that red blood cells are larger than average. The presence of large blood cells is referred to as macrocytosis. Corpuscular is an adjective based on corpuscle, which is a single red or white blood cell.