In pulmonary function tests (PFT) findings for asthma, which of the following is true?

In pulmonary function tests (PFT) findings for asthma, which of the following is true?

• A. FEV1/FVC is greater than 70%
• B. FEV1 is less than predicted
• C. FVC is decreased
• D. TLC is lower than predicted

Answer: (B)

In the context of pulmonary function tests (PFTs) for asthma, one key aspect is understanding the characteristics of airflow limitation associated with this condition. Asthma is primarily characterized by reversible airway obstruction, which can be assessed through measures such as Forced Expiratory Volume in 1 second (FEV1) and Forced Vital Capacity (FVC). In asthma, FEV1 is typically less than the predicted value due to the obstructive nature of the disease that makes it difficult for patients to exhale forcefully. When asthmatic patients experience bronchoconstriction, inflammation, or increased mucus production, this results in reduced airflow and consequently a lower FEV1. Since the FEV1/ FVC ratio often remains normal or only slightly reduced in asthma (and typically is not less than 70% in mild cases), the significant finding is the reduced FEV1 value itself when compared to predicted levels, confirming the presence of airflow obstruction. FVC, on the other hand, usually remains normal in asthma unless there are other complications present, and total lung capacity (TLC) is typically not lower than predicted in asthmatic individuals. These characteristics underline why the statement regarding FEV1 being less than predicted correctly reflects the pulmonary function

In the context of pulmonary function tests (PFTs) for asthma, one key aspect is understanding the characteristics of airflow limitation associated with this condition. Asthma is primarily characterized by reversible airway obstruction, which can be assessed through measures such as Forced Expiratory Volume in 1 second (FEV1) and Forced Vital Capacity (FVC).

In asthma, FEV1 is typically less than the predicted value due to the obstructive nature of the disease that makes it difficult for patients to exhale forcefully. When asthmatic patients experience bronchoconstriction, inflammation, or increased mucus production, this results in reduced airflow and consequently a lower FEV1. Since the FEV1/ FVC ratio often remains normal or only slightly reduced in asthma (and typically is not less than 70% in mild cases), the significant finding is the reduced FEV1 value itself when compared to predicted levels, confirming the presence of airflow obstruction.

FVC, on the other hand, usually remains normal in asthma unless there are other complications present, and total lung capacity (TLC) is typically not lower than predicted in asthmatic individuals. These characteristics underline why the statement regarding FEV1 being less than predicted correctly reflects the pulmonary function