lung function test

Definition of lung function test
National Cancer Institute

lung function test

(… FUNK-shun …)
A test used to measure how well the lungs work. It measures how much air the lungs can hold and how quickly air is moved into and out of the lungs. It also measures how much oxygen is used and how much carbon dioxide is given off during breathing. A lung function test can be used to diagnose a lung disease and to see how well treatment for the disease is working. Also called PFT and pulmonary function test.

Source: NCI Dictionary of Cancer Terms