'autoimmune' originates from Greek and Latin elements: the prefix 'auto-' (from Greek 'autos') meaning 'self' combined with 'immune' (from Latin 'immunis').

'autoimmune' originally appeared in scientific and medical usage as the hyphenated form 'auto-immune' in early 20th-century literature and later consolidated into the single word 'autoimmune'.

Initially built from elements meaning 'self' + 'exempt/protected', it evolved in medical contexts to mean 'an immune response directed against the self' and now specifically describes self-targeting immune processes or conditions caused by them.