What to Expect and Why They’re Important

Understanding Pulmonary Function Tests (PFTs)

Pulmonary function tests (PFTs) are essential tools in diagnosing and managing respiratory conditions. Whether you’re dealing with chronic obstructive pulmonary disease (COPD), asthma, or other lung issues, PFTs help provide a clear picture of how well your lungs are functioning. If your pulmonologist has recommended these tests, it’s natural to have questions. This article will guide you through what to expect during the tests and why they are so critical to your respiratory health.

What are Pulmonary Function Tests (PFTs)?

Pulmonary function tests are a series of non-invasive tests that measure various aspects of how well your lungs are working. These tests evaluate how much air your lungs can hold, how quickly you can exhale, and how efficiently your lungs can transfer oxygen into your bloodstream. PFTs are crucial for diagnosing conditions such as asthma, COPD, pulmonary fibrosis, and other respiratory diseases.

The most common PFTs include:

  • Spirometry: Measures the amount of air you can inhale and exhale, as well as how quickly you can exhale.
  • Lung Volume Measurement: Evaluates the total amount of air your lungs can hold.
  • Diffusion Capacity Test: Assesses how efficiently oxygen moves from your lungs into your blood.

These tests help your doctor better understand the severity of your condition, monitor progression, and guide treatment options.

Why Are PFTs Important?

Pulmonary function tests are a series of non-invasive tests that measure various aspects of how well your lungs are working. These tests evaluate how much air your lungs can hold, how quickly you can exhale, and how efficiently your lungs can transfer oxygen into your bloodstream. PFTs are crucial for diagnosing conditions such as asthma, COPD, pulmonary fibrosis, and other respiratory diseases.

  • Accurate Diagnosis
    PFTs provide detailed measurements that help physicians accurately diagnose lung conditions. For example, they can differentiate between obstructive diseases like COPD, where airflow is restricted, and restrictive diseases like pulmonary fibrosis, where the lungs are less able to expand.
  • Monitoring Disease Progression
    For patients with chronic conditions, PFTs offer an objective way to monitor disease progression. Your doctor can compare results over time to see how your lung function is changing, allowing them to adjust your treatment plan if necessary.
  • Treatment Effectiveness
    PFTs are also used to evaluate how well treatments are working. If you’re on medications, such as bronchodilators or inhalers, PFTs can show whether your lung function improves after using these treatments.
  • Pre-Surgical Assessment
    Before undergoing surgery, especially procedures involving the heart or lungs, PFTs are often performed to assess how well your lungs can handle the stress of anesthesia and surgery.
  • Occupational Health
    In some cases, PFTs are used to monitor the lung health of individuals exposed to lung irritants, such as those working in construction or manufacturing, where inhalation of harmful particles is a concern.

What to Expect During a Pulmonary Function Test

The idea of lung tests might sound intimidating, but PFTs are generally straightforward, painless, and easy to perform. Here’s what to expect for the most common tests:

01

Spirometry

  • What It Does: Measures how much air you can exhale and how fast.
  • The Process: You’ll be asked to sit comfortably and breathe into a mouthpiece attached to a spirometer machine. After taking a deep breath in, you’ll blow out as hard and fast as possible. You may need to repeat the test several times to ensure accuracy.
  • How Long It Takes: The spirometry test typically lasts 10 to 15 minutes.

02

Lung Volume Measurement

  • What It Does: Measures the total volume of air your lungs can hold.
  • The Process: For this test, you may be asked to sit in a clear, sealed box, sometimes called a body plethysmograph, and breathe into a mouthpiece. The pressure changes in the box help measure the air volume in your lungs.
  • How Long It Takes: This test usually takes 15 to 30 minutes.

03

Diffusion Capacity Test

  • What It Does: Measures how well oxygen moves from your lungs to your bloodstream.
  • The Process: You’ll breathe in a harmless gas, and sensors will measure how much of that gas moves from your lungs into your blood.
  • How Long It Takes: This test takes around 10 minutes.

04

Post-Bronchodilator Testing

In some cases, your doctor may want to test your lung function before and after using a bronchodilator (a medication that opens the airways). This helps determine how responsive your lungs are to treatment and is common in diagnosing asthma and COPD.

Preparing for a Pulmonary Function Test

Your doctor will give you specific instructions to follow before the test to ensure accurate results. These may include:

  • Avoid smoking for at least 4-6 hours before the test.
  • Avoid using bronchodilators or other medications that affect your airways unless your doctor instructs otherwise.
  • Wear comfortable clothing that won’t restrict your breathing.
  • Eat lightly before the test, as a full stomach can make it harder to breathe deeply.

It’s important to follow these instructions to ensure the test results are as accurate as possible.

After the Test: Understanding Your Results

After your PFTs, your doctor will interpret the results. While the specific numbers may be complex, your physician will explain what they mean in terms of your lung health. The results may show:

  • Normal lung function: Indicating no significant impairment.
  • Obstructive lung disease: Suggesting that your airways are narrowed, as seen in conditions like COPD or asthma.
  • Restrictive lung disease: Indicating that your lungs are not expanding as they should, which is common in diseases like pulmonary fibrosis.

The results will guide your doctor in making a diagnosis, evaluating the severity of any existing conditions, and creating a treatment plan tailored to your needs.

Pulmonary function tests are invaluable tools in diagnosing and managing respiratory conditions. By measuring how well your lungs are working, PFTs provide your healthcare team with the information they need to tailor treatments and improve your quality of life. Whether you’re newly diagnosed or managing a chronic lung condition, regular PFTs can help track your progress and ensure that your treatment is as effective as possible.

If your pulmonologist has recommended pulmonary function testing, remember that these tests are key to understanding your lung health. Don’t hesitate to ask your healthcare provider any questions or voice concerns about the testing process—your care team is there to help you every step of the way.

You are not alone

Mid-Atlantic Pulmonary and Sleep Medicine is dedicated to providing comprehensive care for patients with respiratory and sleep disorders.

If you or a loved one is facing a lung condition, contact us today to learn how we can support you on your health journey.