What should you know about a computerized spirometer?

A spirometer is connected to a mouthpiece and records breathing as you follow coached instructions. The main readings describe the volume of air exhaled and the speed of the blow. The test can help explore cough, wheeze, breathlessness, or suspected narrowing of the airways, and can show how readings change after an inhaled medicine. A computer displays curves and values, but the printout is not a diagnosis by itself. Effort, technique, recent illness, and the quality of each attempt affect interpretation.

Wear comfortable clothing and follow the clinic's instructions about smoking, meals, exercise, and inhalers. Tell the tester about chest pain, recent surgery, a respiratory infection, pregnancy, or medicines that may affect breathing. During the test, seal your lips around the mouthpiece, fill your lungs as directed, and blow out hard and steadily until told to stop. Several attempts are common because consistent technique makes the readings more useful. You may feel briefly light-headed; pause and tell the tester if that happens.

Seek urgent help for severe breathlessness at rest, blue or grey lips, chest pain, confusion, coughing blood, or an inability to speak in full sentences. Contact a clinician promptly if cough or wheeze is worsening, symptoms repeatedly wake you, or your reliever inhaler is not lasting as expected. Do not delay emergency care while waiting for a spirometry appointment.

Which inhalers or medicines should I use or pause before testing? What do the volume and flow readings suggest? Do I need repeat spirometry, bronchodilator testing, or another assessment?