What is the purpose of a pulmonary function test?

The purpose of a pulmonary function test is primarily to evaluate how well the lungs are working, particularly focusing on their capacity to inhale and exhale air, as well as how effectively gases are exchanged. This assessment includes measuring lung capacity, airflow, and the overall ability of the respiratory system to meet the body’s demands.

While assessing lung expansion is crucial in understanding lung function, the test provides more comprehensive data, including the volume of air the lungs can hold. This information is essential for diagnosing conditions such as asthma, chronic obstructive pulmonary disease (COPD), and other respiratory illnesses.

The other options, although relevant to respiratory health, do not capture the core focus of a pulmonary function test. For instance, measuring resting heart rate pertains to cardiovascular health, while evaluating blood oxygen levels typically requires different tests, such as pulse oximetry or arterial blood gas analysis. Thus, the primary goal of a pulmonary function test aligns best with understanding lung capacity, making it a critical tool in respiratory assessments.