factors affecting normal red cell values

Last reviewed 07/2023

Factors that determine 'normal' red cell parameters include:

  • age:
    • in neonates, delay in cutting the umbilical cord elevates red cell levels
    • the haemoglobin level is high at birth
    • the haemoglobin falls before increasing again towards the end of the first year
    • the numbers of red cells then remains reasonably stable at about 11.5 g/dl, attaining normal adult values at about ten years

  • sex:
    • haemoglobin concentration is higher in men than women
    • this may be due to stimulatory effects of androgens on erythropoietin production and a direct effect on erythroid stem cells

  • menopause, childbirth and pregnancy lead to lower erythrocyte counts

  • nutritional status:
    • parameters lower in poorer people
    • associated with protein and iron deficiency

  • residential altitude:
    • high altitude associated with a compensatory increase in erythrocyte count