What should you know about BTPS spirometry?

A spirometer records how much air you breathe out and how quickly you can do it. Air inside the lungs is warm and humid, while air in testing equipment may be cooler and drier. BTPS correction allows the reported values to represent lung conditions more fairly. The test may help assess asthma, COPD, bronchiectasis or a persistent cough; the result is interpreted alongside symptoms, examination findings and medical history.

Follow the clinic’s instructions about inhalers, smoking, meals and strenuous exercise. Wear clothing that lets your chest expand. During testing, sit upright, seal your lips around the mouthpiece and follow the technician’s instructions for a full breath in followed by a forceful, complete breath out. Several attempts may be needed. Bring a list of medicines and ask whether any inhaler should be used before or after the appointment.

Contact a clinician if breathlessness, wheezing, chest pain or dizziness develops during or after the test, especially if it does not settle with rest. Seek urgent help for severe breathing difficulty, blue or grey lips, confusion, fainting or inability to speak in full sentences. A test result alone does not explain sudden worsening; symptoms need prompt assessment.

Ask which measurements were abnormal, whether the pattern suggests airflow narrowing or reduced lung volume, and whether repeat testing is needed. You can also ask how your inhaler technique or smoking history may affect interpretation.