Definition: Spirometry is a test a doctor uses for confirming the diagnosis of asthma. A spirometer is device that measures the total amount of air you can exhale after taking a deep breath in, as well as the speed by which you are exhaling.
Spirometry is one of the main tools used to diagnose asthma, but it is not accurate in children who are younger than age 6. That can make asthma hard to confirm in very young children.

