Spirometry is a diagnostic test measuring lung function by assessing the volume and flow of inhaled and exhaled air. This non-invasive procedure aids in diagnosing respiratory conditions such as asthma, chronic obstructive pulmonary disease (COPD), and pulmonary fibrosis. During spirometry, a person inhales deeply and then exhales forcefully into a device called a spirometer. The results, including vital capacity and forced expiratory volume, help evaluate lung health, identify abnormalities, and guide treatment decisions. Spirometry is a valuable tool for monitoring respiratory diseases, assessing lung function impairment, and optimizing patient care.