To ensure the ideal ability to carry oxygen and exchange it with tissues, red blood cells must have a number of characteristics, among which is volume. Too large a size will cause difficulty in the passage of blood cells through the smallest capillaries, a small value will lead to insufficient hemoglobin content inside. And in fact, and in another case, the risk of hypoxia increases - oxygen starvation with the ensuing consequences for the whole organism.
Normal MCV is 80-100 fl (femtoliter) - normocytosis. The decrease in this indicator is called "microcytosis" and is typical for:
Water-electrolyte imbalance in plasma, when the concentration of salts in the extracellular environment increases or the amount of fluid decreases. To maintain balance, fluid moves from the intracellular environment to the outside, which results in a decrease in the capacity of the cells themselves. This condition is characteristic of dehydration (indomitable vomiting, diarrhea, extensive burns, water shortage and thirst in hot conditions, loss of moisture with increased sweating), renal and endocrine pathology;
Assumption of the presence of parasites (jaundice, emaciation, indigestion, intestinal upset, bloody discharge from the anal canal, muscle pain, eosinophilia);
Decreased synthesis of hemoglobin due to iron deficiency or changes in its metabolism in the body, as well as in genetic diseases (thalassemia) and sideroblastic anemia;
Toxic damage to the bone marrow (lead poisoning).
Macrocytosis - an increase in the average RBC volume over 100 fl. Observed in the case of:
Lack of folic acid and vitamin B12 is the most common cause;
Hypothyroidism;
Hepatic dysfunction, especially with alcohol damage;
Long-term use of oral contraceptives, cytostatics (powerful antibiotics, immunosuppressants and anticancer drugs).
Determination of MCV in combination with other erythrocyte indices (MCH, MCHC, HCT and RDW) significantly increases the clinical value of a complete blood count, allows for differential diagnosis of anemia. The last point is very important, since different types of anemia can have fundamentally different approaches to treatment and prevention.
