Pulmonary Function Testing

Pulmonary function testing, also known as PFT, is a crucial test that assesses the functionality of our lungs. It provides detailed insights into how well our lungs are functioning. This test is commonly recommended by doctors when patients exhibit symptoms of a lung condition, have been exposed to hazardous gases, suffer from asthma, or need to evaluate lung performance prior to surgery. Typically taking 15 to 45 minutes to complete, a Pulmonary Function Test offers valuable information about lung health.

Benefits of Pulmonary Function Testing:

These are some benefits of the Pulmonary Function Test:

  • This test determines how well you breathe and how well the Oxygen is supplied to your body.
  • Keeping track of how one’s lungs work helps doctors design the treatment. It also works for the early detection of various lung diseases.
  • Doctors suggest Pulmonary Function Testing or Lung Function testing to know the functioning of your body.
  • If a person is already suffering from a lung disease, this test helps doctors check the progress or effects of the treatment.

Pulmonary Function Testing also helps doctors in diagnosing the following lung problems:

  • Asthma
  • Chronic Bronchitis
  • Respiratory infections
  • Lung Fibrosis
  • Bronchiectasis
  • Lung Fibrosis
  • Asbestosis
  • Sarcoidosis
  • Scleroderma

Types of Pulmonary Function Tests:

Pulmonary Function Tests (PFTs) play a crucial role in diagnosing various respiratory conditions. There are several types of PFTs that serve different purposes. These types include:

  • Spirometry: This common PFT measures the volume of air you can inhale and exhale over a given time period, helping assess lung function.
  • Lung Volumes: This test determines the amount of air present in the lungs at different phases of breathing, aiding in detecting lung capacity.
  • Gas Exchange Testing: This PFT measures the transfer of oxygen from air sacs to the blood, providing insights into respiratory efficiency.
  • Maximal Voluntary Ventilation: This test gauges the maximum amount of air you can inhale and exhale in one minute, assessing overall lung function.
  • Inspiratory and Expiratory Muscles Pressures: This test evaluates the strength of the muscles involved in breathing, aiding in identifying respiratory muscle weakness.
  • Oxygen Titration Test: This PFT assesses the oxygen needs of patients who are already on oxygen therapy, helping determine optimal oxygen levels.
  • Six-Minute Walk Test: This test measures how far you can walk in six minutes and assesses your functional capacity for daily activities.
  • Methacholine Challenge Test: This test is used to diagnose asthma by having patients inhale Methacholine solution and measure their breathing response.
  • Cardiopulmonary Exercise Testing: This PFT evaluates your exercise tolerance and cardiovascular fitness, providing insights into your physical capabilities.
  • Fractional Exhaled Nitric Oxide: This test helps diagnose various breathing disorders by measuring the amount of nitric oxide in your breath.
  • Compliance Testing: This PFT assesses the elasticity of the lungs, aiding in the diagnosis of respiratory diseases that affect lung compliance.

High Altitude Simulation Testing: This test helps doctors evaluate blood oxygen content at high altitudes, providing crucial information for individuals who reside or travel to high altitudes.

How to Get Ready For a Pulmonary Function Testing

Prior to undergoing a Pulmonary Function Test (PFT), it is important to refrain from taking medications for asthma or other lung diseases. Additionally, pain-related medications should also be avoided to ensure accurate test results.

In addition, it is advisable to consult with a doctor and confirm any medication routines prior to a Pulmonary Function Test (PFT). It is important to avoid consuming large meals, chocolates, tea, coffee, or any food containing caffeine, as well as refraining from smoking or engaging in strenuous exercise on the day of the examination. Wearing loose clothing during the test and taking rest after its completion is also recommended for optimal results.

Risk of Pulmonary Function Test

It's important to be aware of potential risks associated with pulmonary function testing. Individuals should avoid undergoing pulmonary function tests if they have recently experienced a heart attack, eye surgery, chest surgery, abdominal surgery, respiratory infection, or heart disease. During the test, one may experience dizziness or shortness of breath due to the rapid inhalation and exhalation required. Fainting can also occur in some cases. If an individual has asthma, there is a risk of experiencing an asthma attack during the test. It's crucial to discuss any concerns or medical conditions with your healthcare provider before undergoing pulmonary function testing.

Measurements Drawn From a Pulmonary Function Test

Below is a list of various types of Pulmonary Function Tests (PFTs) and their definitions:

  • Forced Vital Capacity (FVC): The amount of air forcefully exhaled after taking a deep breath.
  • Forced Expiratory Volume in One Second (FEV1): The amount of air forcefully exhaled in the first second.
  • Total Lung Capacity (TLC): The total amount of air in the lungs after a full breath.
  • Forced Expiratory Volume (FEV): The amount of air forcefully exhaled in the first and third seconds.
  • Expiratory Flow Rate (EFR): A measure of the amount of air exhaled.
  • Forced Expiratory Flow (FEF): The volume or flow of air exhaled.
  • Functional Residual Capacity (FRC): The amount of air in the lungs after normal breathing.
  • Maximum Voluntary Ventilation (MVV): The amount of air inhaled and exhaled in one minute.
  • Minute Volume: The amount of air exhaled per minute.
  • Vital Capacity (VC): The total amount of air exhaled after inhaling to the maximum limit.
  • Tidal Volume: The amount of air inhaled and exhaled during normal breathing.

It's important to discuss with a healthcare professional to determine which PFTs are necessary for your specific condition and to interpret the results accurately.


The Pulmonary Function Test (PFT) is a diagnostic procedure used to assess lung capacity and detect various lung-related health conditions. These tests are often recommended by doctors before and after surgeries. It is important to adhere to all the rules and regulations when undergoing a PFT to ensure accurate results.

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