Hutchinson spirometer: what it measures

A spirometer records breathing measurements while you breathe through a mouthpiece. During spirometry, you usually take a full breath and then blow out as hard and as long as instructed. The results can show how much air the lungs hold and how quickly air leaves them.

Clinicians use the pattern to investigate symptoms such as breathlessness, cough, wheeze, or reduced exercise tolerance, and to help assess conditions including asthma or chronic obstructive pulmonary disease. The device does not identify every cause of breathing difficulty by itself; results are interpreted alongside your history and examination.

Wear comfortable clothing and follow the clinic's instructions about meals, smoking, exercise, and inhalers before the appointment. Tell the clinician if you have a recent chest infection, chest pain, an operation, or feel unwell. Bring a list of medicines and inhalers, because some may need specific instructions before testing.

During the test, seal your lips around the mouthpiece and follow the technician's coaching. Several attempts may be needed to obtain consistent readings. You may feel briefly light-headed or tired after forceful blowing; tell the clinician immediately if you feel unwell.

Spirometry is not a substitute for urgent assessment. Seek emergency help for severe breathlessness, blue lips, confusion, fainting, or sudden chest pain. Contact a clinician if breathing symptoms are worsening, waking you at night, or limiting ordinary activity, even if a previous breathing test was reassuring.

Why do you recommend spirometry for my symptoms? Which medicines should I take or pause before the test? How will the results affect the next step, and could I need repeat testing or another assessment?