Diffusion capacity of carbon monoxide (DLCO)

DLCO, or diffusion capacity of carbon monoxide, measures how effectively gases can move from the lungs into the bloodstream. During a test, a person breathes in a small amount of carbon monoxide, and then breathes out. The test assesses how much of that gas is absorbed by the blood, indicating the efficiency of the lungs' gas transfer. It helps doctors evaluate lung health, especially in conditions like fibrosis, emphysema, or pulmonary vascular disease, by providing insight into the lungs' ability to exchange oxygen and carbon dioxide.