Pulmonary Function Tests (PFT) are a group of tests to measure the function of lung capacity and to evaluate the lung and chest wall mechanics to determine whether the patient has a respiratory problem.
From one expiratory forceful maneuver, we can calculate different values which varies from person to person: - Simple screening spirometry. - Lung volume and lung capacities estimation. - Diffusing capacity. - Airway resistance and strength of respiratory muscle. - Exhaled Nitric oxide estimation ( eN0 ) . It is best used in screening of any obstructive airway disease and restrictive disease of lung/chest wall. PFT has become a compulsory investigation prior to job applications in various industries and companies. Also it is an important test to evaluate patients prior to surgery, especially those with smoking history, elderly patients and those with known lung disorders. Children above the age of 4 years are eligible to perform this test.