Pulmonary function tests (PFTs) are non-invasive diagnostic tests that provide measurable feedback about the function of the lungs. By assessing lung volumes, capacities, rates of flow, and gas exchange, PFTs provide information that, can help diagnosis certain lung disorders.
In a spirometry test, a person breathes into mouthpiece that is connected to an instrument called a spirometer. The spirometer records the amount and the rate of air that is breathed in and out over a specified time. Some of the test measurements are obtained by normal, quiet breathing, and other tests require forced inhalation or exhalation after a deep breath.
Pulmonary Function Tests are used for the following reasons: