'bacteremia' originates from New Latin/modern medical formation, specifically from the combining of 'bacterium' (from Greek 'bakterion') and the Greek-derived suffix '-emia' (from 'haima'), where 'bakterion' meant 'small rod' (referring to bacteria) and 'haima' meant 'blood'.

'bacteremia' was formed in modern medical English by combining the Neo-Latin 'bacterium' (itself from Greek 'bakterion') with the suffix '-emia' (from Greek 'haima'). The element 'bacterium' entered scientific Latin/English in the 19th century, and the compound 'bacteremia' arose in clinical usage to denote bacteria in the blood.

Initially it meant 'the presence of bacteria in the blood', and this medical meaning has remained essentially the same in modern usage.