According to the American Lung Association, lung function tests–aka pulmonary function tests–are a collection of exams used to evaluate how well your lungs are currently working.
The most rudimentary of the lung function tests is known as spirometry; this exam quantifies how much air your lungs are able to hold. It also measures how much force you can put into expelling air. Spirometry also screens for diseases such as asthma and COPD, which may alter a person’s lung volume.
Another type of lung function test which is more precise than spirometry is known as lung volume testing. This exam measures the volume of air held in the lungs, as well as how much air remains inside them at the end of an average breath.
Other types of lung function tests include:
- Diffusing capacity tests, which measure how easy it is for oxygen to enter your bloodstream.
- Exercise testing, which look into the causes behind shortness of breath.
Lung function tests are painless and non-invasive. They do, however, generally involve using maximal effort to breathe in and expel air.