CPFT Practice Exam 2025 – Complete Test Prep Guide

Spirometry is the primary pulmonary function test used to assess the presence of obstructive lung disease. This test measures how much air a person can inhale and exhale, as well as how quickly they can do so. Specifically, it evaluates key metrics such as forced expiratory volume in one second (FEV1) and forced vital capacity (FVC).

In obstructive lung diseases, such as asthma and chronic obstructive pulmonary disease (COPD), patients typically exhibit a reduced FEV1 and a normal or even increased FVC. This imbalance results in a decreased ratio of FEV1 to FVC, which is a hallmark of obstructive pathology. By analyzing these measurements, healthcare providers can determine the degree of obstruction in the airways, which is critical for diagnosis and management.

The other tests mentioned serve different purposes. Lung volume measurement provides insights into total lung capacity and can distinguish between obstructive and restrictive lung diseases but is not primarily focused on diagnosing obstructive disorders. The diffusion capacity test assesses how well gases transfer from the lungs to the bloodstream, which is more relevant in evaluating conditions affecting gas exchange rather than airway obstruction. Lung compliance testing measures the lung's ability to stretch and expand, providing information mainly about the lung's elasticity and mechanics rather