Lung function tests, also known as pulmonary function tests, or PFTs, are a group of tests that check to see if your lungs are working right. The tests look for:
How much air your lungs can hold
How well you move air in and out of your lungs
How well the lungs move oxygen into your bloodstream. Your blood cells need oxygen to grow and stay healthy.
There are several types of lung function tests. They include:
Spirometry. the most common type of lung function test. It measures how much and how quickly you can move air in and out of your lungs.
Lung volume test. also known as body plethysmography. This test measures the amount of air you can hold in your lungs and the amount of air that remains after you exhale (breathe out) as much as you can.
Gas diffusion test. This test measures how oxygen and other gases move from the lungs to the bloodstream.
Exercise stress test. This test looks at how exercise affects lung function.