Function of a spirometer

You breathe through a mouthpiece connected to the device while a nose clip may help prevent air escaping through your nose. The spirometer turns your breath into measurements of airflow and air volume. A clinician may ask for a normal breath, a deep breath, and a forceful breath out. The results can show patterns that fit narrowed airways, reduced lung expansion, or a change after an inhaled medicine. The device measures breathing; it does not by itself name the cause of an abnormal result.

Follow the testing instructions about meals, smoking, exercise, and inhalers, because these can affect the reading. Sit upright, seal your lips around the mouthpiece, and follow the technician’s instructions for each attempt. A strong, steady exhalation is often needed, and several attempts may be requested so the team can compare the quality of the blows. Wear comfortable clothing and mention chest pain, dizziness, or a recent infection before testing.

Tell the testing team immediately if you develop chest pain, marked breathlessness, faintness, or severe coughing during the procedure. Outside the test, urgent care is appropriate for sudden severe breathing difficulty, blue or grey lips, confusion, or an inability to speak in full sentences. A routine spirometry appointment should not delay assessment of rapidly worsening breathing.

Ask what the test is investigating, whether any medicines need to be paused, how the result will be interpreted with your symptoms, and whether repeat testing or another lung assessment is needed.