How Asthma Patients Benefit from Pulmonary Function Tests


Asthma is a chronic respiratory condition that affects millions of individuals worldwide. It is characterized by inflammation and narrowing of the airways, leading to symptoms such as wheezing, shortness of breath, chest tightness, and coughing. Managing asthma requires a comprehensive approach, including accurate diagnosis, monitoring, and treatment adjustments based on the patient’s condition. Pulmonary Function Tests (PFTs) play a crucial role in assessing lung function and providing valuable information for effective asthma management. This article explores the benefits of PFTs for asthma patients, highlighting their significance in diagnosis, monitoring, and treatment decision-making.

 Understanding Pulmonary Function Tests 

Pulmonary Function Tests are a series of non-invasive procedures used to evaluate lung function. They measure various parameters, including lung volumes, capacities, airflow rates, and gas exchange. PFTs provide objective measurements of lung function, allowing healthcare professionals to assess the severity of respiratory conditions and monitor changes over time.

Diagnosis and Differential Diagnosis of Asthma:

  1. Confirmation of Asthma Diagnosis: PFTs are instrumental in confirming an asthma diagnosis by evaluating the presence of airflow obstruction and assessing its reversibility. Spirometry, a commonly performed PFT, measures the volume and flow of air during forced expiration. In asthma, spirometry often shows reduced forced expiratory volume in one second (FEV1) and the ratio of FEV1 to forced vital capacity (FVC). The measurement of the reversibility of airflow obstruction after bronchodilator administration helps distinguish asthma from other respiratory conditions.
  2. Differential Diagnosis: PFTs aid in differentiating asthma from other respiratory disorders that exhibit similar symptoms, such as chronic obstructive pulmonary disease (COPD) or vocal cord dysfunction. By comparing PFT results and patterns, healthcare professionals can accurately identify the underlying condition, leading to appropriate treatment strategies.

What is PFT diagnosis for asthma? 

Pulmonary Function Tests (PFTs) are essential in diagnosing asthma by evaluating lung function and airflow obstruction. One of the most commonly performed PFTs for asthma diagnosis is spirometry. Spirometry measures the volume and flow of air during forced expiration. In individuals with asthma, spirometry often shows reduced forced expiratory volume in one second (FEV1) and a decreased ratio of FEV1 to forced vital capacity (FVC). These findings indicate airflow limitation and obstruction in the lungs.

Assessing Asthma Severity and Monitoring Progression:

  • Objective Measurement of Lung Function: PFTs provide quantitative data on lung function, allowing healthcare professionals to classify asthma severity accurately. Spirometry measures, such as FEV1, FVC, and the ratio of FEV1 to FVC, help determine the level of obstruction and airflow limitation. These measurements are essential for categorizing asthma severity according to established guidelines, aiding in personalized treatment planning.
  • Monitoring Treatment Response: Regular PFTs assist in tracking the effectiveness of asthma management strategies. By comparing serial PFT results, healthcare professionals can evaluate changes in lung function over time, enabling them to make necessary treatment adjustments. PFTs are especially helpful in assessing bronchodilator responsiveness, as increased post-bronchodilator values indicate positive treatment response.
  • Identifying Exacerbations: PFTs can help identify impending asthma exacerbations. A decrease in lung function, as indicated by a decline in FEV1, often precedes exacerbations. Early recognition of declining lung function allows healthcare providers to intervene promptly, preventing severe exacerbations and improving patient outcomes.

What is the duration of PFT test?

The duration of a Pulmonary Function Test (PFT) can vary depending on the specific tests being performed and the individual’s ability to cooperate during the procedure. On average, a complete PFT session can take approximately 30 to 60 minutes. However, it’s important to note that this is just an estimated range and the actual duration can be shorter or longer depending on various factors.

The PFT session typically involves a series of tests that evaluate different aspects of lung function. These may include spirometry, lung volumes, diffusion capacity, and bronchial provocation tests. Each test requires specific maneuvers and measurements to be performed, which can contribute to the overall duration of the PFT session.

Guiding Treatment Decisions:

  1. Individualized Treatment Planning: PFT results assist in formulating personalized asthma treatment plans. They provide an objective assessment of lung function and aid in determining the appropriate intensity of medication, including the use of inhaled corticosteroids, long-acting beta-agonists, or other bronchodilators. PFTs help optimize asthma therapy, ensuring patients receive the right medications at the right doses.
  2. Identifying Treatment Complications: PFTs help identify potential complications associated with asthma treatment. For example, long-term use of inhaled corticosteroids can lead to systemic side effects, including reduced bone density and adrenal suppression. Monitoring lung function through PFTs helps detect early signs of treatment-related complications, allowing healthcare professionals to modify therapy accordingly.

Asthma Education and Patient Empowerment:

  • Enhancing Patient Understanding: PFTs play a crucial role in educating asthma patients about their lung function. By visualizing their test results, patients gain a better understanding of their condition’s severity and progression. This knowledge empowers them to actively participate in their treatment plan, adhere to medication regimens, and make lifestyle modifications to manage their asthma effectively.
  • Encouraging Self-Management: Regular PFTs foster self-management skills in asthma patients. By monitoring their lung function at home using peak flow meters, patients can detect early changes in airflow and take appropriate action. This proactive approach helps prevent exacerbations and encourages patients to seek prompt medical attention when necessary.


Pulmonary Function Tests (PFTs) are invaluable tools for asthma management. From diagnosis and differential diagnosis to assessing severity, monitoring treatment response, and guiding treatment decisions, PFTs provide objective measurements of lung function. They empower asthma patients to actively participate in their care, leading to improved outcomes. As healthcare professionals continue to leverage PFTs in asthma management, their use will undoubtedly contribute to better understanding, treatment, and control of this chronic respiratory condition.