Respiratory health is a critical aspect of overall well-being, and the diagnosis and management of respiratory conditions are paramount to improving patient outcomes. Pulmonary function tests (PFTs) play a crucial role in assessing lung function, aiding in the identification and monitoring of various respiratory disorders. In Australia, the presence of specialized pulmonary function test laboratories has significantly contributed to advancing respiratory care.

Types of Pulmonary Function Tests 

Australian Pulmonary function tests (PFTs) encompass a variety of tests that assess different aspects of lung function. These tests help healthcare professionals evaluate respiratory health, diagnose respiratory disorders, monitor disease progression, and assess treatment efficacy. Here are some of the commonly performed types of pulmonary function tests:


  • Spirometry is the most widely used and fundamental PFT. It measures the amount of air a person can forcefully exhale and the speed at which it is exhaled. Spirometry provides essential information about lung capacity, airflow limitations, and the presence of obstructive or restrictive lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), and interstitial lung diseases.

Lung Volume Measurement:

  • Lung volume measurement tests evaluate the total lung capacity (TLC), residual volume (RV), and functional residual capacity (FRC). These tests, including plethysmography and helium dilution, help in assessing lung volumes, identifying restrictive lung diseases, and monitoring disease progression.

Diffusing Capacity Assessment:

  • Diffusing capacity tests, such as the single-breath carbon monoxide diffusing capacity (DLCO), measure the ability of the lungs to transfer gases from the alveoli into the bloodstream. DLCO provides insights into the efficiency of gas exchange, helping in the diagnosis and monitoring of conditions like emphysema, pulmonary fibrosis, and pulmonary hypertension.

Bronchial Provocation Testing:

  • Bronchial provocation tests assess airway hyperresponsiveness, which is a characteristic of asthma. These tests involve inhaling substances like methacholine or histamine to induce temporary airway constriction, and the degree of airway narrowing is measured to determine the presence and severity of asthma.

Exercise Testing:

  • Exercise testing evaluates lung function during physical exertion. It helps assess exercise-induced bronchoconstriction, exercise capacity, and exercise tolerance. This type of test is valuable in managing conditions like asthma, COPD, and evaluating fitness levels.

How do you measure breath strength?

Breath strength, also known as respiratory muscle strength, can be measured using various techniques. These measurements provide valuable information about the strength and function of the respiratory muscles, which play a crucial role in lung ventilation. Here are some common methods for assessing breath strength:

Maximal Inspiratory Pressure 

  1. MIP measures the maximum force generated during a deep inhalation against a closed airway. The person inhales as forcefully as possible through a mouthpiece connected to a pressure gauge. MIP reflects the strength of the inspiratory muscles, including the diaphragm and the muscles between the ribs (intercostal muscles).

Peak Expiratory Flow 

  1. PEF measures the maximum airflow rate achieved during a forceful exhalation. It is commonly assessed using a handheld peak flow meter. The person takes a deep breath and then exhales as forcefully and rapidly as possible into the meter. PEF provides an estimate of overall respiratory muscle strength and can be used to monitor conditions such as asthma and chronic obstructive pulmonary disease (COPD).

Forced Vital Capacity

  1. FVC is a measurement of the maximum volume of air forcefully exhaled after a deep inhalation. It is typically measured using spirometry, which records the volume and flow of air during breathing maneuvers. FVC reflects the combined strength of both inspiratory and expiratory muscles and is a useful parameter for evaluating lung function.

These measurements are usually performed in a clinical setting by healthcare professionals, such as respiratory therapists.

What is a normal breath holding capacity?

Breath-holding capacity refers to the ability to hold one’s breath comfortably after a maximal inhalation or exhalation. The duration of breath-holding can vary among individuals and may be influenced by factors such as age, fitness level, and lung function. It is important to note that breath-holding capacity is different from lung capacity, which measures the maximum volume of air that can be inhaled or exhaled.

On average, a healthy adult with normal lung function can hold their breath for approximately 30-60 seconds. However, individual variations are common, and some individuals may be able to hold their breath for longer durations, especially those who have received specific training or practice breath-holding techniques.

Applications of pulmonary function test laboratory

Pulmonary function test (PFT) laboratories play a crucial role in respiratory healthcare, offering a range of applications in diagnosing, managing, and monitoring various respiratory conditions. Here are some key applications of pulmonary function test laboratories:

Diagnosing Respiratory Disorders:

  • PFT laboratories aid in the diagnosis of respiratory conditions by assessing lung function and identifying abnormalities. PFTs can help diagnose conditions such as asthma, chronic obstructive pulmonary disease (COPD), interstitial lung diseases, restrictive lung diseases, bronchiectasis, and neuromuscular disorders.

Assessing Disease Severity and Progression:

  • PFTs provide valuable information about the severity and progression of respiratory disorders. By measuring lung volumes, airflow rates, and gas exchange capabilities, PFTs help healthcare professionals evaluate disease severity, monitor disease progression, and assess the effectiveness of treatments.

Monitoring Treatment Efficacy:

  • PFTs are utilized to assess the response to various respiratory treatments, including bronchodilators, corticosteroids, and oxygen therapy. By conducting PFTs before and after treatment, healthcare providers can determine the effectiveness of therapies and make appropriate adjustments to the treatment plan.


Australian Pulmonary function tests laboratory and breath analysis have transformed respiratory healthcare by providing valuable diagnostic information and enabling personalized treatment strategies. With ongoing technological advancements and research, the future of PFTs holds immense promise, allowing for more accurate assessments, early detection of respiratory disorders, and improved patient outcomes.

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