Spirometry is a type of pulmonary function test that measures the amount of air taken in (volume) and exhaled as a function of time.
During a spirometry test, a patient places their mouth over the mouthpiece of the spirometer, takes a deep breath in, and then blows out as forcefully as possible.
Spirometry gives health care professionals two important numbers that may indicate problems with lung function. These are:
- Forced Vital Capacity (FVC) - how much air you can blow out of your lungs
- Forced Expiratory Volume (FEV1) - the amount of air you can blow out in 1 second
Your doctor may use the results of your spirometry to diagnose emphysema or asthma. If you have a lung disease such as asthma, this test can give important information on whether or not medications are working, or if your disease is worsening. With lung cancer, spirometry may help your doctor decide if you would be able to tolerate lung cancer surgery.