Why does haemotocrit decrease in acute blood loss?

[sameeralord]

In acute blood loss both RBC and fluid is lost, so why doesn't haemotocrit stay normal. I know compensatory mechanism would increase the fluid, eg kidney. But red blood cell prodcution would take few weeks. Is that the reason haemotocrit decreases? Thanks :smile:

[aroc91]

Indeed. Plasma would be restored way before RBC count.

[walshlg]

The decrease in mechanical pressure results in a reballance of intersititial fluid (eg think the opposite of edema).