'anhydraemia' originates from Greek, specifically the combining forms 'an-' meaning 'without', 'hydr-' from 'hydōr' meaning 'water', and '-aemia' from 'haima' meaning 'blood; condition of the blood.'

'Anhydraemia' was coined in Neo-Latin/modern medical Latin from Greek elements; it entered English medical terminology in the 19th century as the British spelling, while the American spelling became 'anhydremia'.

Initially, it meant 'lack of water in the blood,' and this meaning has remained essentially unchanged in modern usage.