Pulmonary Function Tests
Our doctors use pulmonary function tests to determine how well your lungs work to give you the most personal care.
A Closer Look at How Your Lungs Work
- Understand how well your lungs work compared to how they should work
- See the impact of chronic diseases like asthma, chronic obstructive lung disease (COPD), interstitial lung disease, pulmonary hypertension or cystic fibrosis on your lungs
- Catch early changes that can help you have the best treatment and outcomes
- Detect narrowing of the airways
- Show whether specific substances in your home or workplace may have harmed your lungs
- Determine your tolerance for surgery or procedures
Types of PFTs & what to expect
There are several types of PFTs. The most common are spirometry, methacholine challenge testing, diffusion studies and body plethysmography. Your doctor may need you to do just one or sometimes will schedule more than one on the same day. The testing could take 45 to 90 minutes, based on the type ordered.
Spirometry tests
A machine called a spirometer measures how much air you can breathe in and then how much you can breathe out of your lungs fast. During this common PFT, you’ll take a deep breath and forcefully blow all of the air out into a tube connected to the machine. You’ll repeat the test three times with breaks in between. This test takes about 30 minutes to complete.
You may take the test again in the future after taking a breathing medicine. Follow your doctor’s orders regarding whether you should take your medicine beforehand.
Methacholine challenge testing
Methacholine inhalation helps your doctor measure how reactive your lungs are to aid in the diagnosis of asthma. During the test, you’ll inhale increasing amounts of this medicine, which narrows your bronchial airways. How much your airways narrow is measured by a spirometer. Also known as the bronchoprovocation test, this common procedure is considered safe. However, as it can cause a tightening of the airways, you may experience symptoms of an asthma attack. Our team will watch you closely and, if needed, will give you a bronchodilator to relieve your symptoms.
Diffusion studies
Diffusion tests find out how well the oxygen in the air you breathe moves from your lungs into your blood. You’ll breathe into a mouthpiece connected to a machine for this test. Gently empty out the air in your lungs followed by a quick, deep breath in. You’ll hold your breath for 10 seconds and breathe out. You will repeat this test several times in about 30 minutes. If you’re on oxygen, you’ll be asked to remove your oxygen shortly before taking the test. Refrain from smoking on the day of the test.
Body plethysmography
This test measures the amount of air in your lungs after you breathe in deeply and what remains after you breathe out as fully as you can. (No one can fully empty their lungs.) This test helps your pulmonologist understand how well your lungs are working and helps the doctor create your personalized treatment plan.
For about 15 minutes, you’ll sit in a small space with windows that you can see through. You’ll wear a mouthpiece and a nose clip. You will receive instructions on how to breathe, taking short, shallow breaths. If you’re on oxygen, you’ll be asked to remove your oxygen for a few minutes before taking the test. Tell your physician if you have claustrophobia when ordering this test. There may be testing alternatives available.
Before the test
Ask your healthcare provider if you should stop taking certain medicines, including breathing medicines. Sometimes you’ll need to stop your medicines four to 24 hours before the test. Follow instructions from the healthcare provider to prepare yourself for the test.
These tests may not be performed if you have chest pain, dizziness, elevated blood pressure or severe shortness of breath.
After the test
You may go back to your normal diet and medications unless instructed otherwise by your healthcare provider.
Learn more about lung care at Wellstar and find a pulmonologist near you.