Spirometry is a test that measures the amount of air a person's lungs can move in and out and at what rate.

To be tested:

• The person places his or her mouth on the mouthpiece that is attached to a recording device (spirometer).
• The person breathes in (inhales) as deeply as possible.
• The person then blows out (exhales) as hard, fast, and completely as possible.

This test can be done in a doctor's office or the hospital and is not painful.