# autoimmune

/ˌɔˈtɔɪmjun/ (US) · /ˌɔːtəʊɪmjˈuːn/ (UK) · CEFR C1 · Adjective

Source: https://englishreference.com/word/autoimmune
Updated: 2026-05-07

## Definition

describing a condition where your body's defense system makes a mistake and attacks your own healthy cells. It is like your body's army fighting against itself instead of fighting germs.

For teachers: relating to a condition in which the immune system mistakenly identifies the body's own tissues as foreign antigens and attacks them. Often used to modify nouns like 'disease', 'disorder', or 'response'.

## Examples

- Lupus is a common autoimmune disease.
- The doctor ordered blood tests to check for an autoimmune reaction that might be causing the joint pain.
- Research into autoimmune pathologies suggests that a combination of genetic predisposition and environmental triggers can cause the immune system to lose its ability to distinguish self from non-self.

## Usage notes

- Typically used attributively before a noun; often paired with 'disease', 'disorder', or 'condition'.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.