'anosognosia' originates from modern medical coinage based on Greek, specifically the word 'anosognōsia', where 'a-' meant 'without', 'nosos' meant 'disease', and 'gnōsis' meant 'knowledge'.

'anosognosia' was introduced in early 20th-century neurology (often attributed to descriptions by physicians such as Joseph Babinski and contemporaries) as a technical term to describe patients' lack of awareness of their deficits; it was formed from Greek elements rather than evolving through Old or Middle English.

Initially, it meant 'absence of knowledge about one's disease', and this core meaning has remained, though modern use can apply broadly to various forms of unawareness of neurological or psychiatric deficits.