What Is A Pulmonary Function Test?
Pulmonary Function Tests (PFTs) measure how well your lungs are working by measuring how much air your lungs can hold, how quickly you can blow air out of your lungs, how well gas is transferred from the lungs to your bloodstream, and how well your lungs respond to pulmonary medications. The test will look for two kinds of respiratory disorders: obstructive and restrictive.
Occurs when air flow out of the lungs is limited.
Occurs when lung or chest wall expansion is decreased, which limits the volume of air brought into the lungs.
What Are the Reasons to Get Pulmonary Function Testing?
Your provider may recommend a Pulmonary Function Test if you are experiencing any of these symptoms:
- Shortness of breath or difficulty breathing
- Presence of workplace exposure to lungs-damaging chemicals
- Coughing or wheezing
What Conditions IT Helps Diagnose
Pulmonary Function Testing will help your provider diagnose and manage chronic lung diseases such as asthma, chronic obstructive lung disease (COPD), and interstitial lung diseases. These tests provide information about how well your lungs are working. Your provider will use this information to make decisions about your treatment.
Asthma is a long-term lung condition affecting the bronchial tubes requiring different and customized treatment per patient.learn more
When diagnosed with asthma after the age of 20, it is defined as adult-onset asthma and is typically considered chronic.learn more
Asthma is one of the most common long-term diseases but with proper care and treatment, kids can live completely normal lives.learn more
Types of Pulmonary Function Tests
Spirometry is a very common pulmonary function test that measures the volume of air that you’re able to blow out in a forceful and rapid manner. Depending on your symptoms, your provider may also give you a medication that you breathe in that is designed to open up the airways, at which point your spirometry will be re-measured.
The measurement of lung volumes tells us how much air is in your lungs after you take in a deep breath and how much air is left in your lungs after breathing out as much as you can.
No matter how hard you try, you can never get rid of all of the air from your lungs.
Six-Minute Walk Test
The six-minute walk test is just like it sounds. It measures the distance you are able to walk in six minutes on a hard, flat surface.
Exhaled Nitric Oxide Test
An exhaled nitric oxide level test can help diagnose and manage asthma. It measures the amount of nitric oxide that is exhaled from a breath.
Increased levels of nitric oxide are associated with inflammation of the lung airways. This test can be used to determine whether someone being treated for asthma is responding well to certain medications.
Lung Diffusion Capacity
Lung diffusion capacity measures how well the lungs allow gases to “diffuse” or pass into the blood from the lungs on inspiration and pass from the blood back into the lungs on expiration.
*Note: that not all of these different tests will be performed at each visit. Which tests are performed will depend on your symptoms and what your provider orders.
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Pulmonary Function Tests Side Effects and Risks
You will be closely monitored during the test and your provider will be prepared to address any discomfort or concerns. The risks associated with a pulmonary function test are small but patients may rarely experience:
- Dizziness during the tests
- Feeling short of breath
- Coughing or wheezing
In some cases, patients shouldn’t undergo testing IF:
- They have had recent surgery on their stomach, chest, eye, ear or brain.
- They have chest pain, recent heart attack, or an unstable heart condition.
- Have a bulging blood vessel (aneurysm) in the chest, stomach, or brain.
- Have active tuberculosis (TB) or respiratory infection, such as a cold or the flu.
Pulmonary Function Test Results
Most of the time, your allergist will have your test findings accessible right away and go over them with you. They may suggest more tests or adjustments to your existing treatment plan based on the findings. Your PFT results will be evaluated in relation to those of a wide population of individuals with similar demographics to your own (height, gender, age, and ethnicity).
Pulmonary Function Tests FAQ
Why do I need a PFT?
PFT results provide helpful information to assist your provider in determining the cause of your cough, shortness of breath, difficulty breathing, and/or wheezing. For those patients who already have a pulmonary diagnosis, PFTs performed serially over time help track the progression of your disease and help guide adjustments to your treatment plan.
Can I eat or drink before taking a PFT?
You can eat and/or drink prior to the PFT, although it is recommended to avoid eating a large meal before your test.
How will my body be positioned for a PFT?
You will be sitting or standing, at the discretion of your provider.
How do you know what a “normal” result is?
Your PFT measurements will be compared to the expected average values of a large group of other patients of the same height, gender, age, and ethnicity.