Pulmonology Function Test
Learn about the Pulmonology Function Test.
What is Pulmonology Function Test?
Pulmonary Function Tests (PFTs) are non-invasive tests to show how well the lungs are working.
The Pulmonology Function Tests measure lung volume, capacity, rates of flow, and gas exchange.
Why the Test is Performed
PFTs are performed to determine whether you have an obstructive or restrictive lung disorder. Obstructive lung disorders involve decreased airflow due to airway resistance. Restrictive lung disorders occur when the lungs can’t expand enough and airflow is restricted. PFTs may be performed because they are part of a routine physical, because of the type of environment you work in (factory or mine), or if your doctor suspects a health problem such as allergies, respiratory infections, trouble breathing, chronic lung conditions, and other issues.
How to Prepare for the Test
Your doctor will need to know all medications and supplements you are taking. Your doctor will tell you if you need to stop any medications prior to the test. Stop smoking, do not eat a heavy meal, and follow any other instructions provided by your doctor. Your doctor will record your height and weight before the test for the most accurate results.
What Happens During the Test
You will be asked to loosen clothing, remove jewelry, or other things that may cause a problem with the accuracy of the test. If you wear dentures, you will need to wear them for the test. You will need to use the bathroom prior to the test. You will be seated and a soft clip will be placed on your nose so all of your breathing is done through your mouth only. Your doctor will give you a sterile mouthpiece attached to a spirometer. Form a tight seal over the mouthpiece with your mouth while you inhale and exhale. Your doctor may give you a bronchodilator (medication to assist with breathing) after certain tests, and then the tests will be repeated.
What is Monitored During the Test
PFTs measure the following:
- Amount of air inhaled or exhaled during normal breathing (Tidal volume)
- Total amount of air exhaled per minute (Minute volume)
- Total volume of air that can be exhaled after inhaling as much as you can (Vital capacity)
- Amount of air left in lungs after exhaling normally (Functional residual capacity)
- Amount of air left in the lungs after exhaling as much as you can (Residual volume)
- Total volume of the lungs when filled with as much air as possible (Total lung capacity)
- Amount of air exhaled forcefully and quickly after inhaling as much as you can (Forced vital capacity)
- Amount of air expired during the first, second, and third seconds of the FVC test (Forced expiratory volume)
- Average rate of flow during the middle half of the FVC test (Forced expiratory flow)
- Fastest rate that you can force air out of your lungs (Peak expiratory flow rate)
What Equipment is Used
A spirometer: a machine used to measure lung capacity and airflow in the diagnosis of breathing disorders
Potential Risks of the Test
PFTs are relatively safe. Some possible risks may include:
- Dizziness during the tests
- Feeling short of breath
- Coughing
- Asthma attack brought on by deep inhalation
You should not have a PFT if you have had recent eye surgery, belly or chest surgery, recent heart attack, aneurysm in the chest, belly, or brain, active respiratory infection such as the cold or flu.