Spirometry and peak airflow tests are among the most commonly used pulmonary function tests which measure how fast and how much air you can breathe in and out these tests can also be used to differentiate between an obstructive lung disease such as copd and a restrictive lung disease such as pulmonary fibrosis. Laboratory evaluation of pulmonary function american review of respiratory disease 1371 p 246. Pulmonary function tests pfts are noninvasive tests that show how well the lungs are working the tests measure lung volume capacity rates of flow and gas exchange this information can help your healthcare provider diagnose and decide the treatment of certain lung disorders. Pulmonary function tests have become integral to the evaluation of pulmonary patients this has led to the establishment of pulmonary function laboratories generally with computerized printouts in most hospitals patients can be tested and the results made available to physicians fairly promptly but the system does not lend itself to the proper integration of physiologic testing into the