What should you know about no known drug allergies?

This statement is a medication-history entry used to alert a healthcare team that you have not identified a previous drug allergy. It is different from saying that every medicine has been tested in you. Side effects such as nausea, diarrhoea, or headache are not automatically allergies, although they should still be described accurately. A true allergic reaction may involve hives, swelling, wheezing, or a sudden drop in blood pressure. Anaphylaxis is a severe, rapid allergic reaction.

Tell every clinician and pharmacist about past reactions, including the medicine name, timing, symptoms, and treatment needed. Mention reactions that happened after an injection, cream, eye drop, or over-the-counter product. Do not remove an allergy label because a medicine was tolerated once; ask a clinician to review the record. If a past reaction is unclear, a [GP Consultation](/treatments/consultations-and-assessment/gp-consultation/) can help decide whether specialist review or [Allergy Testing](/treatments/diagnostics-and-screening/allergy-testing/) is useful.

After a medicine, get emergency help for difficulty breathing, throat or tongue swelling, faintness, widespread hives, or rapidly worsening symptoms. Stop and seek prompt advice for a new rash, facial swelling, wheeze, or repeated vomiting after a dose. Do not restart a suspected medicine without professional guidance. Read more about [Anaphylaxis](/conditions/anaphylaxis/).

Ask how to distinguish an allergy from a side effect, which details belong in your record, and whether a past reaction warrants testing or an emergency action plan.