Bronchitis and spirometry: what to know

During spirometry, you breathe into a spirometer through a mouthpiece. The test records airflow while you take a full breath and exhale forcefully. Clinicians may repeat the manoeuvre to check consistency and may compare readings before and after a prescribed bronchodilator. Acute coughing can make the effort difficult, so testing may be planned when the infection has settled. Spirometry does not by itself explain every cough, and it is not usually needed to label a short-lived episode of uncomplicated acute bronchitis. Persistent cough, wheeze or exertional breathlessness may prompt assessment for asthma, COPD, bronchiectasis or chronic cough.

Follow the testing centre’s instructions about meals, smoking and inhalers; some medicines may need timing changes, but only a clinician should advise you to pause a prescribed treatment. Wear comfortable clothing and tell the tester about chest pain, recent surgery, dizziness or an infection. The manoeuvre requires a firm seal around the mouthpiece and a strong, sustained exhalation. You can stop if you feel unwell and tell the staff immediately.

Seek urgent help for severe breathing difficulty, blue or grey lips, fainting, confusion, coughing blood or significant chest pain; do not wait for a lung function appointment. Arrange review if cough, wheeze or breathlessness continues after the acute illness, keeps returning, or limits activity. A clinician can decide whether spirometry, imaging or another test is suitable.

Why do you recommend spirometry in my case? Should I change the timing of my inhaler before testing? Could the result point to asthma, COPD or bronchiectasis? When should the test be repeated?