I got this doubt when I was studying about haematocrit value. According to my NCERT textbook males have greater number of RBCs than females. But who will have more RBCs when comparing a normal male and a female who lives at a higher altitude?


the magnitude of altitude would be less than 8,586 m (28,169 ft) as the woman I know is not exactly at the top summit of Kanchenjunga so what would be the answer then?


closed as primarily opinion-based by Chris, rg255, The Last Word, Cornelius, Bez Jul 1 '14 at 19:07

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.

  • $\begingroup$ Why should it be different there? $\endgroup$ – Chris Jul 1 '14 at 12:08
  • $\begingroup$ @Chris i didn't get you $\endgroup$ – agha rehan abbas Jul 1 '14 at 12:12
  • $\begingroup$ en.wikipedia.org/wiki/High-altitude_adaptation $\endgroup$ – Raghavakrishna Jul 1 '14 at 12:14
  • $\begingroup$ @Raghavakrishna i have read that article but my doubt is who will have more no. of RBCs now a normal male living at normal sea level or a female living at higher altitude? because normally males have more no or RBCs when compared with females $\endgroup$ – agha rehan abbas Jul 1 '14 at 12:17
  • $\begingroup$ @agharehanabbas You can not compare this directly since the conditions are completely different. And if men and women are both at high altitude, I would expect men again to have higher counts. $\endgroup$ – Chris Jul 1 '14 at 12:19

Currently impossible to give a definite answer... It depends what altitude you look at.

Going from @Alan_boyd's answer the normal range is 40-50% for males and 36-44% for females. If the altitude at which a person is acclimatized to correlates well with red blood cell count (RBCC), and this effect is not gender specific (i.e. both sexes are affected similarly), then an average woman from high altitude should have a higher RBCC than an average from low altitude. But whether or not the high altitude female RBCC exceeds that of the male depends on the altitude of the two measured.

This rough graph, assuming RBCC and altitude correlate and that male RBCC is higher than female RBCC, shows the problem. Female (red dashed line) A is from a higher altitude than the selected male (blue dashed line) and has lower RBCC. Female (red dashed line) B is from a higher altitude than the selected male (blue dashed line) and has higher RBCC.

enter image description here

Define altitudes and the question may be answerable.

  • $\begingroup$ i have edited my question now what must be the answer $\endgroup$ – agha rehan abbas Jul 1 '14 at 13:06

According to the MedlinePlus site these are the normal ranges for haematocrit:

Male: 40.7 - 50.3%

Female: 36.1 - 44.3%

Unfortunately it isn't clear if these ranges are for people living at low altitude, but since most people in the USA do, I think this is a safe inference. So clearly there is already some overlap.

The paper accessible here reports various changes in haematocrit due to moving between different altitudes. Broadly speaking these changes are in the range of 10 - 15 percentage points (e.g. a change from 39% to 49%).

So yes, a female who has moved to a high altitude is likely to experience an erythrocytosis (or polycythaemia) which would mean that her haematocrit would exceed that of many males.


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