The breathing test that measures how well your lungs work. Most of the prep is about your inhalers and what to avoid before — here is the plain-English version.
Spirometry is the standard test for how well your lungs are working. You take a deep breath in, then blow out as hard and as fast as you can into a mouthpiece. The machine measures how much air you can breathe out and how fast. It is the main test used to diagnose and monitor asthma and COPD (emphysema/chronic bronchitis), and is sometimes used before surgery or to check work-related lung exposures.
The test is safe, painless, and usually takes 15–30 minutes.
If the test is being used to diagnose lung disease, or to see how much your reliever opens up your airways, you will usually be asked to stop your inhaler for a set time before the test. This is so the test shows your lungs in their baseline state.
Always check with the practice doing your test — they may give different instructions for your situation. Below are the typical withhold times.
| Inhaler type | Common brand names in Australia | Withhold before test |
|---|---|---|
| Short-acting reliever (SABA) | Ventolin, Asmol, Airomir (salbutamol); Bricanyl (terbutaline) | 4–6 hours |
| Short-acting anticholinergic (SAMA) | Atrovent (ipratropium) | 12 hours |
| Long-acting reliever, twice-daily (LABA) | Seretide, Symbicort, Foradile, Oxis, Serevent | 24 hours |
| Long-acting reliever, once-daily (LABA) | Breo (vilanterol) | 36 hours |
| Long-acting anticholinergic (LAMA) | Spiriva (tiotropium); Bretaris/Eklira (aclidinium); Seebri (glycopyrronium); Incruse (umeclidinium) | 36–48 hours |
| Combined LABA + LAMA | Anoro, Spiolto, Ultibro, Brimica, Bevespi, Trelegy | 36–48 hours (follow the LAMA) |
| Inhaled corticosteroid (preventer) | Flixotide, Pulmicort, Alvesco, Arnuity, Qvar | Usually continue as normal |
| Theophylline tablets | Nuelin SR | 12–24 hours |
Withhold times from the TSANZ / National Asthma Council Spirometry Handbook 2023 and ATS/ERS 2019 Standardization of Spirometry.
Bring all your inhalers with you on the day — even the ones you have been asked to skip. The practice may want to:
Eat normally — spirometry is not a fasting test. A light meal is fine. Avoid a very heavy meal in the 2 hours before.
Drink water — normal hydration is fine.
Take your other regular medicines (blood pressure, cholesterol, etc.) as usual, unless told otherwise. Only inhalers and theophylline tablets need to be withheld.
Continue your preventer inhaler (inhaled corticosteroid like Flixotide, Pulmicort, Alvesco, Qvar) as normal.
Bring a list of all your inhalers — with the name, strength, and how often you use each one.
No smoking or vaping for at least 1 hour before (ideally 24 hours if the test is for COPD diagnosis).
No vigorous exercise in the 1 hour before.
No alcohol in the 8 hours before.
No large or heavy meal in the 2 hours before — a full stomach can make it harder to take a deep breath.
No tight clothing around your chest, waist, or neck (tight belts, corsets, restrictive bras, neckties).
The test is not painful. You may feel a little light-headed for a few seconds afterwards — this is normal and passes quickly. Some people cough.
Phone the practice and reschedule if any of the following apply:
Can I have a coffee on the morning of my spirometry?
There is no strict rule against coffee for a standard spirometry test, but some practices ask you to skip caffeine for a few hours because it can mildly affect the airways. If unsure, ask the practice doing your test.
I forgot and used my Ventolin this morning — should I cancel?
Don’t cancel — phone the practice and tell them. Most can either go ahead and note it on your result, or shift the appointment by a few hours so the reliever wears off.
Do I have to stop my preventer inhaler too?
Usually no. Inhaled corticosteroid preventers (Flixotide, Pulmicort, Alvesco, Arnuity, Qvar) are continued as normal — they do not affect the immediate spirometry result. If your inhaler is a combination (preventer plus long-acting reliever like Seretide, Symbicort, or Breo), follow the long-acting reliever rule (24 hours).
Does spirometry cost anything?
If done at a bulk-billing GP practice, usually no out-of-pocket cost. Some practices charge a private fee for the spirometry test itself, separate from the GP consultation. Ask the practice when you book.