# epinephrine

/ˌɛpɪˈnɛfɹɪn/ (US) · /ˈɛpɪnˌɛfɹiːn/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/epinephrine
Updated: 2026-05-30

## Definition

a hormone and medicine that your body makes when you are in danger. It helps your heart beat faster and makes your body ready to run or fight.

For teachers: a hormone and neurotransmitter secreted by the adrenal medulla in response to stress. It functions as a medication to treat anaphylaxis and cardiac arrest by increasing heart rate and blood pressure.

## Examples

- The doctor gave the patient an injection of epinephrine.
- Patients with severe allergies carry an epinephrine auto-injector to manage life-threatening reactions immediately.
- The sudden release of epinephrine during a traumatic event triggers the fight-or-flight response, redirecting blood flow to the muscles and increasing glucose levels in the bloodstream.

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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.