Breathe Easier: How Pulmonary Function Testing Helps Patients

Pulmonary function testing (PFT) is a valuable diagnostic tool that helps providers understand how well a patient’s lungs are working. Whether someone is experiencing unexplained breathing symptoms or managing a known lung condition, these tests provide important insights that guide diagnosis, treatment, and ongoing care.

What is pulmonary function testing?

As respiratory therapist Lindsay Branby explains, “pulmonary function testing measures how effectively the lungs move air in and out and how well oxygen enters the bloodstream.”

PFT is not a single test, but rather a group of tests that evaluate different aspects of lung function. Together, they give providers a more complete picture of how well the lungs are working.

How the testing works

Pulmonary function tests are performed by Lindsay at the Perham Health’s Nelson Therapy Center. Testing is done while the patient is seated inside a body box.

“The body box kind of looks like a phone booth, and helps us measure air volume. The patient breathes through a mouthpiece, with a nose clip in place to ensure accurate measurements. There are a few different types of tests. During each one, you breathe a little bit differently. You will not be asked to do anything physical. It’s not scary at all,” she explains.

Depending on the test, patients may be asked to:

• Take a deep breath and blow out as hard as possible
• Breathe normally or rapidly (panting) against resistance
• Hold their breath for a short period

The entire process usually takes between 20 and 45 minutes.

Testing can be performed on both adults and children, though cooperation is important for accurate results. “Typically, if kids are five or older, and can perform the breathing exercises, we can complete the test,” Lindsay notes.

Patients do need a referral from their provider.

Types of pulmonary function tests

There are several types of pulmonary function tests, each designed to measure a specific aspect of lung performance and help identify potential problems.

• Spirometry: One of the most common tests, spirometry measures how much air a person can inhale and exhale, and how quickly. It can be used to show changes in lung function due to medications.
• Diffusion capacity (DLCO): This test evaluates how well oxygen moves from the lungs into the bloodstream. It involves taking a breath in, holding it briefly, and then exhaling.
• Lung volume testing: This measures the total amount of air in the lungs, including the air that remains after exhaling.
• Plethysmography: This test determines how much air is left in the lungs after breathing out and identifies any resistance in the airways.

Why pulmonary function testing is done

Pulmonary function testing is often used as a starting point when patients experience ongoing respiratory symptoms.

“People come in complaining of a chronic cough that won’t go away, wheezing or shortness of breath,” Lindsay says.

Beyond symptom evaluation, PFTs are also used for:

• Diagnosing lung conditions such as asthma, chronic obstructive pulmonary disease (COPD), bronchitis, emphysema, and interstitial lung disease
• Monitoring disease progression in patients with known respiratory conditions
• Evaluating readiness for surgery, particularly when anesthesia is involved
• Assessing the impact of environmental or occupational exposures
• Monitoring side effects of certain medications that may affect lung function

In many cases, the results help providers confirm a diagnosis and develop an appropriate treatment plan.

Testing helps create personalized treatment plans

One of the key benefits of pulmonary function testing is its ability to provide clear, objective data. Rather than relying on symptoms alone, providers can use measurable results to guide care.

“Everybody is so different, and especially with the lungs. It’s kind of hard to move in the right direction if we’re just guessing,” Lindsay says. “It’s a quick measurement that gives us a baseline and allows providers to create a personalized treatment plan.”

For many patients, testing leads to answers – and relief. In some cases, symptoms like a chronic cough may be identified as asthma, allowing treatment to begin. In others, the testing helps confirm that current therapies are working or need adjustment.

Testing close to home

Having testing available close to home reduces the need for additional appointments and travel, streamlining the care process.

Lindsay emphasizes the importance of bringing these services into the community: “Having this in Perham means patients don’t have to travel to Fargo, and they don’t have to make two separate appointments to get it done.”

A simple, informative tool

By helping providers better understand lung function, PFTs play a key role in diagnosing conditions, guiding treatment, and improving quality of life for patients with respiratory concerns.