Pulmonary Function Testing (PFT), also called a lung function test or spirometry, is a simple, non-invasive test to determine how well your lungs are working. The PFT measures your breathing capacity and how fast the air moves in and out of your lungs. A blood test can also measure your oxygen and carbon dioxide levels.
Pulmonary Function Testing may be used to diagnose shortness of breath or certain lung diseases like asthma, emphysema or COPD. PFT is also used to check lung function before surgery.
What to Expect
Before your test, you will receive specific instructions on how to prepare, including not smoking four to six hours in advance, and refraining from eating a heavy meal the night before. During the test, you will breathe into a mouthpiece that is connected to a spirometer which measures your breathing rate and the volume of air you are moving. For part of the test, you will breathe normally; for other parts, you will need to breathe harder or faster. You may be asked to inhale a harmless tracer gas to help determine how efficiently your lungs move air into your bloodstream.