Lung tests, also known as pulmonary function tests, are medical assessments that measure how well the lungs are working. These tests evaluate lung capacity, airflow, and gas exchange, helping doctors diagnose conditions like asthma, chronic obstructive pulmonary disease (COPD), and other respiratory issues. Common types of lung tests include spirometry, which measures the amount of air you can inhale and exhale, and diffusion capacity tests, which assess how well oxygen passes from the lungs into the bloodstream. These tests are typically non-invasive and can provide valuable information about lung health.