Spirometry, also known as a Pulmonary Function Test (PFT), is a common and highly valuable diagnostic tool used to evaluate how well a person’s lungs are functioning. It measures how much air a person can inhale and exhale, as well as how quickly the lungs can move that air. The test provides critical data on lung capacity and flow rates, helping healthcare providers diagnose, monitor, and manage a range of respiratory conditions.
The procedure is simple and noninvasive. During a spirometry test, a patient breathes into a mouthpiece connected to a spirometer—a device that records the amount and rate of air breathed in and out over a specific period. Patients are typically asked to take a deep breath and then exhale as forcefully and completely as possible. This process may be repeated several times to ensure accuracy, with the highest readings used for interpretation.
The two key values obtained from spirometry are the Forced Vital Capacity (FVC) and the Forced Expiratory Volume in one second (FEV₁). FVC represents the total amount of air that can be forcibly exhaled after taking a deep breath, while FEV₁ measures how much of that air can be exhaled in the first second. The ratio of these two numbers (FEV₁/FVC) is a key indicator used to differentiate between obstructive and restrictive lung diseases.
Spirometry is an essential test for diagnosing conditions such as asthma, chronic obstructive pulmonary disease (COPD), and other disorders that affect breathing. In occupational health settings, spirometry is frequently used to establish baseline lung function for employees who are exposed to respiratory hazards, such as dust, fumes, or chemicals. It can also be a component of respiratory clearance exams for workers who use respirators.
Baseline testing provides a snapshot of an employee’s normal lung function at the start of employment or exposure. Periodic follow-up tests can then detect early signs of lung impairment, allowing employers and clinicians to intervene before more serious conditions develop. This proactive approach not only safeguards employee health but can also help employers maintain compliance with OSHA standards and other regulatory requirements.
In addition to its role in surveillance and screening, spirometry helps evaluate the effectiveness of treatment plans for individuals with known respiratory conditions. For example, patients with asthma may undergo periodic spirometry to determine whether their inhaler regimen is adequately controlling airway inflammation and obstruction. In COPD management, spirometry results can guide decisions about medication adjustments and oxygen therapy.
To ensure accuracy, spirometry must be performed by trained personnel following standardized procedures. Proper technique is crucial, poor seal around the mouthpiece, suboptimal effort, or improper calibration of the spirometer can lead to inaccurate results. Many occupational health clinics, including those in the Franciscan WorkingWell network, utilize equipment that meets or exceeds American Thoracic Society (ATS) standards.
Results from spirometry are typically compared to predicted values based on the individual’s age, sex, height, and ethnicity. These predicted values represent what normal lung function should look like for someone with similar characteristics. Deviations from these norms can indicate either obstructive patterns (such as asthma or COPD, where airflow is restricted) or restrictive patterns (such as pulmonary fibrosis, where lung expansion is limited).
Employees who smoke or have a history of respiratory illness may also benefit from periodic spirometry as part of a wellness or smoking cessation program. Early detection of lung impairment can motivate lifestyle changes and medical intervention before symptoms progress. For employers, offering these screenings demonstrates a strong commitment to workforce health and safety.
Spirometry results are often presented in both numeric and graphical form. The flow-volume loop, a visual graph showing the relationship between airflow and lung volume during inspiration and expiration, can reveal characteristic patterns of disease. Interpreting these loops requires clinical expertise, but they offer valuable insights into airway dynamics that raw numbers alone may not show.
Because the test is quick, typically taking less than 15 minutes, it can be integrated easily into routine occupational or primary care visits. Employees usually experience no side effects, although those with severe respiratory or cardiac issues may need additional medical clearance before testing. After the test, results are reviewed with the patient, and follow-up recommendations are made if abnormalities are detected.
When performed regularly, spirometry establishes a longitudinal record of lung health. This can be particularly important for workers in industries such as manufacturing, firefighting, agriculture, and construction, where airborne exposures are common. Tracking trends over time allows clinicians to identify declines in lung function even before symptoms appear, prompting early intervention.
Overall, spirometry is an essential component of comprehensive occupational and preventive health programs. It supports early detection, guides clinical decisions, ensures regulatory compliance, and promotes overall respiratory wellness in the workforce. At WorkingWell and HEALTHeACCESS locations, spirometry testing is conducted with precision, compassion, and a focus on prevention—helping employees breathe easier and employers maintain healthier, more productive teams.