What should you know about performing spirometry?

You breathe into a spirometer through a clean mouthpiece. The device records the force and volume of your breath. You will usually be asked to breathe in fully, seal your lips around the mouthpiece, and blow out hard for as long as instructed. The test is repeated so the team can judge consistency. Some people repeat it after an inhaled medicine to see whether airflow changes. Results are interpreted with your symptoms, examination and medical history. Spirometry can help assess asthma, COPD, bronchiectasis and some causes of chronic cough.

Wear loose clothing and follow the appointment team’s instructions about meals, smoking and inhaler medicines. Tell them about recent chest illness, surgery, severe pain or dizziness before testing. Sit upright, follow the coaching closely and tell the operator if you feel unwell. Strong blowing can briefly cause coughing, light-headedness or chest tightness; the test can be paused. Do not change prescribed inhalers unless the testing team has specifically told you to.

Tell the operator immediately if you develop severe breathlessness, chest pain, faintness or symptoms that do not settle after stopping. Contact a clinician after the appointment if breathing becomes worse than usual or you need urgent inhaler treatment. Arrange follow-up to discuss results rather than trying to interpret a single measurement alone.

What question is this test intended to answer? Should I use or pause any inhaler beforehand? When will the results be explained, and would repeat testing or another assessment be needed?