What should you know about spirometer measures lung capacity?

The test can record the total air expelled after a full breath in, along with the amount released during the early part of the breath. These measurements help a clinician look for narrowed airways, reduced expansion of the lungs, or a mixture of both. A result is interpreted against factors such as age, height, sex assigned at birth, and the quality of the effort. One reading does not by itself name a disease. Coughing, a poor seal around the mouthpiece, tiredness, or stopping too soon can affect the result.

Follow the testing centre’s instructions about medicines, meals, smoking, and exercise before the appointment. Wear clothing that allows your chest and abdomen to move freely. During the test, sit upright, seal your lips around the mouthpiece, breathe in fully, then blow out hard and keep going until instructed to stop. Several attempts are common because the team checks whether the results are consistent. Tell the clinician if you feel dizzy, develop chest discomfort, or cannot complete a manoeuvre. Bring your inhalers and a list of medicines so the team can explain whether any should be paused.

Seek emergency help for severe breathlessness at rest, blue or grey lips, fainting, new confusion, or chest pain that is severe or persistent. Arrange prompt medical assessment if breathlessness is worsening, wheezing is not settling with your prescribed plan, or you are coughing blood. A spirometry appointment is not a substitute for urgent care. If symptoms arise during testing, tell the staff immediately so they can stop and assess you.

Ask which measurements were obtained, whether the test quality was adequate, and what pattern the results suggest. You can also ask whether the test should be repeated, whether medicine was used before or after testing, and what symptoms should prompt a review.