How allergic asthma is diagnosed

No single symptom or allergy result establishes the diagnosis. The clinician looks for variable airflow narrowing and checks whether exposure to a suspected allergen fits the timing of cough, wheeze, breathlessness or chest tightness.

Your appointment may cover night waking, exercise symptoms, home and work exposures, seasonal changes, smoking or vaping, family allergy history and response to past inhalers. Examination can be normal between episodes, so a clear account of changing symptoms matters.

Spirometry measures how air moves out of the lungs and may be repeated after a bronchodilator. Peak-flow readings taken over time can show variability. Skin-prick or blood testing can demonstrate sensitisation, but a positive allergy test is meaningful only when it matches real-life exposure and symptoms.

Write down where and when episodes happen, possible triggers, sleep disruption and activity limits. Bring every inhaler, spacer and current medicine list. Before a breathing or allergy test, follow the clinic's instructions about medicines; do not stop prescribed treatment unless the clinician specifically tells you to.

If initial results are unclear, follow-up testing may be needed because asthma varies. Other explanations such as upper-airway allergy, reflux, infection or another cause of chronic cough may be assessed alongside it.

Do not wait for routine diagnostic testing if you are struggling to breathe, cannot speak comfortably, develop blue or grey lips, feel faint or confused, or worsen after using prescribed reliever medicine. Seek urgent medical help and use your existing emergency plan if you have one.

You might ask what showed variable airflow, whether the allergy finding matches your symptom pattern, what alternatives are still being considered, and whether you need home peak-flow monitoring. Also confirm how future treatment response will be reviewed.