What should you know about spirometer instrument?

Most spirometers include a mouthpiece, a sensor or flow meter, a display and software that stores or presents readings. The instrument estimates the volume of air exhaled and the speed at which it leaves the lungs. It does not identify a condition by itself. A trained professional checks the manoeuvre, considers whether the tracing is reliable, and interprets it with your symptoms, examination and medical history.

You will usually sit or stand as instructed, breathe in fully, seal your lips around the mouthpiece and blow out as hard and as long as directed. Several attempts may be needed because technique affects the result. Tell the tester if you feel dizzy, develop chest pain, cough repeatedly or cannot continue. Cleaning and disposable mouthpiece arrangements depend on the instrument, so follow the supplied instructions.

Seek emergency care for sudden severe breathlessness, blue or grey lips, confusion, fainting, or an inability to speak in full sentences. Arrange a clinical review for persistent cough, wheeze, chest tightness or breathlessness that limits normal activity. The instrument should support assessment, never postpone it.

Ask what each displayed value means, whether your test was technically adequate, and whether you need testing before or after a prescribed inhaler. Ask how the instrument is cleaned and maintained.