A Pulmonary Function Test is a simple breathing test that measures how well your lungs work. It checks how much air you can inhale and exhale and how efficiently your lungs transfer oxygen into your blood. It is commonly used to diagnose and monitor conditions such as Asthma, Chronic Obstructive Pulmonary Disease, and Pulmonary Fibrosis. The test is non-invasive, painless, and usually takes 30โ60 minutes.