What to know about ATS spirometry

You breathe into a spirometer as fully and forcefully as instructed. Several attempts may be needed because consistent effort helps the clinician decide whether the measurements are reliable. The test can assess airflow limitation and follow change over time, but a result is interpreted alongside symptoms, medical history and examination.

ATS commonly refers to the American Thoracic Society. Its technical approach guides equipment checks, coaching, acceptable breathing manoeuvres and comparison of repeat efforts. A report may include FEV1, the air expelled early in a forced breath, and FVC, the total air forcibly exhaled. Their relationship helps identify an obstructive pattern.

Spirometry can support assessment of asthma or COPD and may be used when investigating chronic cough or monitoring a known lung condition. It does not identify every cause of breathlessness, and an unusual value is not a diagnosis by itself. Sometimes the test is repeated after an inhaled bronchodilator to see whether airflow changes.

Follow the clinic's instructions about inhalers, smoking, meals and strenuous activity before the appointment; do not stop prescribed medicine unless specifically told to. Wear clothing that allows comfortable deep breathing and mention recent chest infection, surgery, heart problems, pregnancy, dizziness or pain with forced breathing.

During testing, seal your lips around the mouthpiece, inhale fully and blow out hard until the operator says to stop. Tell the operator if you become light-headed, develop pain or cannot continue. Ask whether the session met quality criteria and whether follow-up testing or a treatment review is planned.

Seek urgent medical help for severe or rapidly worsening breathlessness, blue or grey lips, confusion, fainting, chest pain, or difficulty speaking in full sentences. These warning signs matter regardless of any previous spirometry result. Contact a clinician promptly if breathlessness, wheeze or cough is new, worsening, waking you at night or limiting normal activity.

Ask what pattern the test showed, whether your efforts met acceptability and repeatability criteria, and which reference range was used. Clarify whether you need bronchodilator testing, repeat spirometry, another lung-function test or a review of inhaler technique.