'hypovolaemia' originates from New Latin, specifically the word 'hypovolaemia', where the prefix 'hypo-' meant 'under' and 'volaemia' combined the idea of 'volume' with the Greek element 'aemia' (from 'haima') meaning 'blood'.

'hypovolaemia' was formed in New Latin from Greek/Latin elements ('hypo-' + 'aemia') and entered modern medical English as 'hypovolaemia'; a common later orthographic variant in American English became 'hypovolemia' (simplifying '-ae-' to '-e-').

Initially used in medical contexts to denote a reduced blood volume, it has retained this specialized medical meaning and is still used to mean 'low circulating blood volume'.