Pulmonary tests for asthma

Spirometry is commonly used to measure how much air you can exhale and how quickly. The clinician may compare readings before and after an inhaled reliever. If symptoms vary, peak-flow readings recorded at home may add useful information. Some people need further testing when initial results are normal but symptoms continue. Cough, wheezing, chest tightness, allergic rhinitis, or exposure to house dust mite allergy may help the clinician understand the pattern, but none of these features confirms asthma alone.

Results can be affected by technique, recent infection, medicines, and whether symptoms are present on the day. A diagnosis should combine test results with your history and examination.

Follow instructions about inhalers, smoking, meals, and exercise. Practise the breathing manoeuvre carefully and tell the operator if you feel dizzy or uncomfortable. Keep a note of triggers, night symptoms, activity limits, and reliever use. Use prescribed inhalers as directed, and ask before changing them for a test.

Seek emergency help for severe or rapidly worsening breathlessness, blue or grey lips, confusion, collapse, or difficulty speaking in full sentences. A reliever that is not helping as instructed also warrants urgent advice. Do not wait for a routine pulmonary test during a severe attack.

Ask which test is planned, whether you need to pause any inhaler, how results will be interpreted, and what to do if symptoms occur before the appointment. Ask for a written action plan if asthma is diagnosed.