Spirometry is one of the most commonly used approaches to test pulmonary function. It measures the volume of exhaled air vs. time. This activity highlights its role in the evaluation of pulmonary disease by the interprofessional team.Spirometry is one of the most readily available and useful tests for pulmonary function. It measures the volume of air exhaled at specific time points during complete exhalation by force, which is preceded by a maximal inhalation.The most important variables reported include total exhaled volume, known as the forced vital capacity (FVC), the volume exhaled in the first second, known as the forced expiratory volume in one second (FEV1), and their ratio (FEV1/FVC). These results are represented on a graph as volumes and combinations of these volumes termed capacities and can be used as a diagnostic tool, as a means to monitor patients with pulmonary diseases and to improve the rate of smoking cessation according to some reports.