MCV stands for mean corpuscular volume. It is the basic element of a standard peripheral blood count and is very useful in the diagnosis of anemia. What are the MCV standards? What does MCV above and below norm mean?

MCV(mean corpuscular volume) stands for the average volume of red blood cells (RBC), also called red blood cells. MCV is most helpful in diagnosing and differentiating the causes of anemia. Erythrocytes are the basic and most abundant blood cells that transport oxygen around the body. They are characterized by the lack of a cell nucleus and the characteristic shape of a biconcave disk.

MCV is an important component of theperipheral blood counttest that can provide valuable information about your current he alth status. Both the reduction and the increase in the volume of the red blood cell may result not only from simple deficiencies, but also from serious diseases that require more extensive diagnosis and treatment.

Any deviation from the norm should be consulted with a doctor. It should be remembered that the MCV value is only one of the elements of the additional test, which is the peripheral blood count, and only its comparison with other parameters and a full clinical examination will allow to draw appropriate conclusions.

MCV: norm

The norm of the mean volume of erythrocytes is usually 82-92 fl (femtoliters; 1fl=1x10-15 liters!).

When MCV drops below the norm, we talk about the so-calledmicrocytosis .

The increase above the upper limit of the reference range is calledmacrocytosis .

MCV decline - what does it mean?

A decrease in the mean red blood cell volumeis in the overwhelming majority of cases associated with the most common type of anemia - iron deficiency anemia.

Iron is an important component of hemoglobin - the protein contained in the red blood cell and responsible for the transport of oxygen. Deficiency of this element in the organism causes impairment of hemoglobin synthesis. Thus, the production of red blood cells is reduced, and the ones that are formed are small - hence the reduced MCV value.

Then we say that we are dealing withmicrocytic anemia . However, you shouldremember that if your anemia is mild and the number of small red blood cells is low, their average presence may sometimes be normal.

The causes of iron deficiency anemia include :

  • blood loss- usually due to:
    • chronic gastrointestinal bleeding (related to e.g. ulcer disease or colorectal cancer)
    • vaginal bleeding (e.g. during heavy periods)
    • following injuries
  • pregnancy (mainly 2nd and 3rd trimester) and lactation
  • puberty (the time of increased iron demand is associated with a higher risk of iron deficiency)
  • iron deficiency in the diet - Fe deficiency may be associated with a vegan or vegetarian diet
  • condition after gastrectomy
  • autoimmune gastritis
  • celiakia
  • diet rich in phytates and oxalates (impair iron absorption)

As you can see, many, sometimes very serious, conditions can be responsible for iron deficiency anemia. For this reason, the cause of your anemia should be determined before startingdeficiency treatment !

Thalassemia, an inherited disease associated with abnormal hemoglobin biosynthesis, may be a much rarer cause of anemia associated with decreased MCV. This disease is more common among the populations living in the Mediterranean basin.

MCV increase - what does it mean?

Increased red blood cell volume is typical of anemia caused by vitamin B12 and folate deficiency.

Macrocytic anemia resulting from vitamin B12 deficiency can lead to :

  • Addison-Biermer disease- the most common cause; the essence of the disease is the presence of autoantibodies directed against the parietal cells of the stomach or the internal factor produced by them, which determines the proper absorption of vitamin B12
  • insufficient supply of vitamin in the diet- the most vitamin B12 is contained in meat and milk, hence improper use of a vegan or vegetarian diet for a long time may cause a deficiency
  • limited absorption of vitamin B12from the gastrointestinal tract caused by, among others :
    • condition after gastric or ileal resection
    • Crohn's disease
    • bacterial growth syndrome
    • chronic pancreatitis
    • long-term abuse of PPIs (pump inhibitorsproton)

The causes of macrocytic anemia resulting from folic acid deficiency include:

  • insufficient consumption of fresh or short-cooked ( <15 min) zielonych warzyw
  • absorption disorder
  • alcoholism
  • taking certain medications, e.g. methotrexate, sulfasalazine, phenytoin

Vitamin deficiencies are not the onlyreasons for the increase in MCV . The following diseases may also be behind the increase of this parameter above the norm:

  • chronic liver disease
  • hypothyroidism
  • end stage renal disease
  • monoclonal gamma
  • myelodysplastic syndrome

Sources:

  1. Interna Szczeklika - practical medicine

Read also:

  • MCHC: low or high value, which means?
  • Basophils, or basophils: BASO standards
  • Monocytes (MONO) - role, norm, excess and deficiency
  • Eosinophils (eosinocytes, EOS): elevated or below normal

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Pregnant examinations