What are lung function tests?
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.
These tests may be used together or by themselves, depending on your specific symptoms or condition.
Other names: pulmonary function tests, PFTs
What are they used for?
Lung function tests are often used to:
- Find the cause of breathing problems
- Diagnose and monitor chronic lung diseases, including asthma, chronic obstructive pulmonary disease (COPD), and emphysema
- See if lung disease treatments are working
- Check lung function before surgery
- Check whether exposure to chemicals or other substances in the home or workplace have caused lung damage
Why do I need a lung function test?
You may need this test if you:
- Have symptoms of a breathing problem such as shortness of breath, wheezing, and/or coughing
- Have a chronic lung disease
- Have been exposed to asbestos or other substances known to cause lung damage
- Have scleroderma, a disease that damages connective tissue
- Have sarcoidosis, a disease that causes damage to cells around the lungs, liver, and other organs
- Have a respiratory infection
- Had an abnormal chest x-ray
- Are scheduled for an operation such as abdominal or lung surgery