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Mean corpuscular volume


The mean corpuscular volume (MCV) is one of the standard red blood cell (RBC) "indices" (table 1). It is the volume of the "average" RBC, stated in femtoliters (fL, 10-15 L). Measurement of the MCV and its importance in the differential diagnosis of anemia will be discussed here [1]. Control of RBC hydration, which directly influences the MCV, is discussed separately. (See "Control of red blood cell hydration".)

A general approach to the patient with anemia is presented separately. (See "Approach to the adult patient with anemia".)


The mean corpuscular volume (MCV) can be measured or calculated in a number of different ways (see "Automated hematology instrumentation"):

Use of volume-sensitive automated blood cell counters, such as the Coulter counter. In this type of apparatus, the red cells pass one-by-one through a small aperture and generate a signal directly proportional to their volume.

Other automated counters measure red blood cell (RBC) volume by means of techniques that measure refracted, diffracted, or scattered light.


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Literature review current through: Mar 2014. | This topic last updated: Oct 30, 2013.
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  1. Brugnara C, Mohandas N. Red cell indices in classification and treatment of anemias: from M.M. Wintrobes's original 1934 classification to the third millennium. Curr Opin Hematol 2013; 20:222.
  2. Saxena S, Weiner JM, Carmel R. Red blood cell distribution width in untreated pernicious anemia. Am J Clin Pathol 1988; 89:660.
  3. Harkins LS, Sirel JM, McKay PJ, et al. Discriminant analysis of macrocytic red cells. Clin Lab Haematol 1994; 16:225.
  4. Eldibany MM, Totonchi KF, Joseph NJ, Rhone D. Usefulness of certain red blood cell indices in diagnosing and differentiating thalassemia trait from iron-deficiency anemia. Am J Clin Pathol 1999; 111:676.
  5. Madan N, Sikka M, Sharma S, et al. Red cell indices and discriminant functions in the detection of beta-thalassaemia trait in a population with high prevalence of iron deficiency anaemia. Indian J Pathol Microbiol 1999; 42:55.
  6. AlFadhli SM, Al-Awadhi AM, AlKhaldi D. Validity assessment of nine discriminant functions used for the differentiation between iron deficiency anemia and thalassemia minor. J Trop Pediatr 2007; 53:93.
  7. Ferrara M, Capozzi L, Russo R, et al. Reliability of red blood cell indices and formulas to discriminate between beta thalassemia trait and iron deficiency in children. Hematology 2010; 15:112.
  8. Schoorl M, Schoorl M, Linssen J, et al. Efficacy of advanced discriminating algorithms for screening on iron-deficiency anemia and β-thalassemia trait: a multicenter evaluation. Am J Clin Pathol 2012; 138:300.
  9. Veeranna V, Zalawadiya SK, Panaich S, et al. Comparative analysis of red cell distribution width and high sensitivity C-reactive protein for coronary heart disease mortality prediction in multi-ethnic population: findings from the 1999-2004 NHANES. Int J Cardiol 2013; 168:5156.
  10. Ueda T, Kawakami R, Horii M, et al. High mean corpuscular volume is a new indicator of prognosis in acute decompensated heart failure. Circ J 2013; 77:2766.
  11. Rezende SM, Lijfering WM, Rosendaal FR, Cannegieter SC. Hematologic variables and venous thrombosis: red cell distribution width and blood monocyte count are associated with an increased risk. Haematologica 2014; 99:194.
  12. Tonelli M, Sacks F, Arnold M, et al. Relation Between Red Blood Cell Distribution Width and Cardiovascular Event Rate in People With Coronary Disease. Circulation 2008; 117:163.
  13. Poludasu S, Marmur JD, Weedon J, et al. Red cell distribution width (RDW) as a predictor of long-term mortality in patients undergoing percutaneous coronary intervention. Thromb Haemost 2009; 102:581.
  14. Kurt M, Tanboga IH, Buyukkaya E, et al. Relation of Red Cell Distribution Width With CHA2DS2-VASc Score in Patients With Nonvalvular Atrial Fibrillation. Clin Appl Thromb Hemost 2013.
  15. Güngör B, Ozcan KS, Erdinler I, et al. Elevated levels of RDW is associated with non-valvular atrial fibrillation. J Thromb Thrombolysis 2013.
  16. Adamsson Eryd S, Borné Y, Melander O, et al. Red blood cell distribution width is associated with incidence of atrial fibrillation. J Intern Med 2014; 275:84.
  17. Providência R, Ferreira MJ, Gonçalves L, et al. Mean corpuscular volume and red cell distribution width as predictors of left atrial stasis in patients with non-valvular atrial fibrillation. Am J Cardiovasc Dis 2013; 3:91.
  18. Kim J, Kim YD, Song TJ, et al. Red blood cell distribution width is associated with poor clinical outcome in acute cerebral infarction. Thromb Haemost 2012; 108:349.
  19. Aung N, Dworakowski R, Byrne J, et al. Progressive rise in red cell distribution width is associated with poor outcome after transcatheter aortic valve implantation. Heart 2013; 99:1261.
  20. Allen LA, Felker GM, Mehra MR, et al. Validation and potential mechanisms of red cell distribution width as a prognostic marker in heart failure. J Card Fail 2010; 16:230.
  21. Lippi G, Sanchis-Gomar F, Danese E, Montagnana M. Association of red blood cell distribution width with plasma lipids in a general population of unselected outpatients. Kardiol Pol 2013; 71:931.
  22. Solak Y, Yilmaz MI, Saglam M, et al. Red cell distribution width is independently related to endothelial dysfunction in patients with chronic kidney disease. Am J Med Sci 2014; 347:118.
  23. Ujszaszi A, Molnar MZ, Czira ME, et al. Renal function is independently associated with red cell distribution width in kidney transplant recipients: a potential new auxiliary parameter for the clinical evaluation of patients with chronic kidney disease. Br J Haematol 2013; 161:715.
  24. Afonso L, Zalawadiya SK, Veeranna V, et al. Relationship between red cell distribution width and microalbuminuria: a population-based study of multiethnic representative US adults. Nephron Clin Pract 2011; 119:c277.
  25. Majercik S, Fox J, Knight S, Horne BD. Red cell distribution width is predictive of mortality in trauma patients. J Trauma Acute Care Surg 2013; 74:1021.
  26. Garbharran U, Chinthapalli S, Hopper I, et al. Red cell distribution width is an independent predictor of mortality in hip fracture. Age Ageing 2013; 42:258.
  27. Balta S, Demirkol S, Hatipoglu M, et al. Red cell distribution width is a predictor of mortality in patients with severe sepsis and septic shock. Am J Emerg Med 2013; 31:989.
  28. Jo YH, Kim K, Lee JH, et al. Red cell distribution width is a prognostic factor in severe sepsis and septic shock. Am J Emerg Med 2013; 31:545.
  29. Balta S, Demirkol S, Cakar M, et al. Red cell distribution width: a novel and simple predictor of mortality in acute pancreatitis. Am J Emerg Med 2013; 31:991.
  30. Şenol K, Saylam B, Kocaay F, Tez M. Red cell distribution width as a predictor of mortality in acute pancreatitis. Am J Emerg Med 2013; 31:687.
  31. Kim HM, Kim BS, Cho YK, et al. Elevated red cell distribution width is associated with advanced fibrosis in NAFLD. Clin Mol Hepatol 2013; 19:258.
  32. Demir R, Saritemur M, Ozel L, et al. Red Cell Distribution Width Identifies Cerebral Venous Sinus Thrombosis in Patients With Headache. Clin Appl Thromb Hemost 2013.
  33. Lam AP, Gundabolu K, Sridharan A, et al. Multiplicative interaction between mean corpuscular volume and red cell distribution width in predicting mortality of elderly patients with and without anemia. Am J Hematol 2013; 88:E245.
  34. Patel KV, Ferrucci L, Ershler WB, et al. Red blood cell distribution width and the risk of death in middle-aged and older adults. Arch Intern Med 2009; 169:515.
  35. Perlstein TS, Weuve J, Pfeffer MA, Beckman JA. Red blood cell distribution width and mortality risk in a community-based prospective cohort. Arch Intern Med 2009; 169:588.
  36. Horne BD, May HT, Muhlestein JB, et al. Exceptional mortality prediction by risk scores from common laboratory tests. Am J Med 2009; 122:550.
  37. Grant BJ, Kudalkar DP, Muti P, et al. Relation between lung function and RBC distribution width in a population-based study. Chest 2003; 124:494.
  38. Garcez ME, Peres W, Salvador M. Oxidative stress and hematologic and biochemical parameters in individuals with Down syndrome. Mayo Clin Proc 2005; 80:1607.
  39. Kobayashi S, Moriya H, Aso K, Ohtake T. Vitamin E-bonded hemodialyzer improves atherosclerosis associated with a rheological improvement of circulating red blood cells. Kidney Int 2003; 63:1881.
  40. Uprichard J, Dorling D, Bain BJ. A dimorphic blood film as a sign of the onset of iron-deficient erythropoiesis in megaloblastic anemia. Am J Hematol 2012; 87:1046.
  41. Planas AT, Van Voolen GA, Kelly LA. Hyperglycemic macrocytosis in electronically determined mean corpuscular volume. Use of three different automatic cell counters. Ann Clin Lab Sci 1985; 15:286.
  42. Holt JT, DeWandler MJ, Arvan DA. Spurious elevation of the electronically determined mean corpuscular volume and hematocrit caused by hyperglycemia. Am J Clin Pathol 1982; 77:561.
  43. van Duijnhoven HL, Treskes M. Marked interference of hyperglycemia in measurements of mean (red) cell volume by Technicon H analyzers. Clin Chem 1996; 42:76.
  44. Hinchliffe RF, Bellamy GJ, Lilleyman JS. Use of the Technicon H1 hypochromia flag in detecting spurious macrocytosis induced by excessive K2-EDTA concentration. Clin Lab Haematol 1992; 14:268.
  45. Kim AH, Jang W, Kim Y, et al. Mean corpuscular volume (MCV) values reflect therapeutic effectiveness in zidovudine-receiving HIV patients. J Clin Lab Anal 2013; 27:373.
  46. Camaschella C. How I manage patients with atypical microcytic anaemia. Br J Haematol 2013; 160:12.
  47. Athiyarath R, Arora N, Fuster F, et al. Two novel missense mutations in iron transport protein transferrin causing hypochromic microcytic anaemia and haemosiderosis: molecular characterization and structural implications. Br J Haematol 2013; 163:404.
  48. Thompson WG, Meola T, Lipkin M Jr, Freedman ML. Red cell distribution width, mean corpuscular volume, and transferrin saturation in the diagnosis of iron deficiency. Arch Intern Med 1988; 148:2128.
  49. Seward SJ, Safran C, Marton KI, Robinson SH. Does the mean corpuscular volume help physicians evaluate hospitalized patients with anemia? J Gen Intern Med 1990; 5:187.
  50. Marsh WL Jr, Bishop JW, Darcy TP. Evaluation of red cell volume distribution width (RDW). Hematol Pathol 1987; 1:117.