Understanding
your spirometry
test results

Kuopio, Finland
February 20, 2024

Spirometry is a critical tool for assessing lung health, particularly for diagnosing, managing, and monitoring conditions such as asthma, chronic obstructive pulmonary disease (COPD), and other respiratory ailments ¹. This article focuses on demystifying the spirometry test results, helping you understand the key metrics and their implications for your lung health and treatment strategy.

Key spirometry test metrics

Understanding your spirometry test results is crucial for managing your respiratory health. The test measures several important lung function metrics, which include:

What is a spirogram? 

A spirogram is an illustrative graph that plots the volume of air your lungs can hold against the flow rate at which you inhale or exhale. The graph presents a curve that reflects the dynamic process of breathing: the peak represents the maximum speed of your exhale (PEF), and the area under the curve corresponds to the volume of air expelled (FVC) and the speed of exhalation in the first second (FEV1).

How is a spirogram being interpreted? 

Spirogram is reflecting your breathing patterns throughout the spirometry test. The shape of the curve on the graph is instrumental in diagnosing specific lung conditions:

• A normal spirometry graph is characterized by a rapid rise in airflow, peaking quickly before a gradual decline. This indicates efficient lung function where air is expelled swiftly and fully.
• In contrast, an obstructive pattern may show a ‘coved’ or scooped-out shape on the flow-volume loop. This pattern is marked by a reduced peak flow and a concave curvature after the peak, signaling airway obstruction that hinders air expulsion. If your FEV1/FVC ratio falls below 70%, it’s a sign of such an obstructive respiratory condition, like asthma or COPD, suggesting partially blocked airways.
• Restrictive patterns exhibit a different spirometry graph with a sharp but lower peak, pointing to a reduced lung volume. The steeper descent to baseline reflects a reduced ability to fill the lungs with air, but not necessarily an issue with expelling it. A below-normal FVC value corroborates this, hinting at restrictive respiratory conditions such as pulmonary fibrosis or scoliosis, where lung expansion is compromised.

Case example can help illustrate the implications of different spirometry results. For instance, an individual with asthma might show a significantly reduced FEV1 during an exacerbation ⁶, which improves with bronchodilator treatment:

What is “normal”?

Understanding your spirometry results in the context of what’s considered normal for your demographic is essential. ‘Normal’ spirometry values are determined by various factors, including age, sex assigned at birth, height, and ethnicity ⁷. To accurately interpret your results, they must be compared against predicted normal values that are specific to these demographic variables.

Medikro Spirometry software addresses this by integrating a database of reference sets, which are essentially collections of healthy individuals’ spirometry measurements across different ethnic backgrounds, ages, and sexes. Before conducting the test, your doctor will select a reference set that matches your demographic profile. The software then uses this information to determine if your spirometry results deviate from what is expected within your peer group.

Results that fall below normal can signal a potential impairment in lung function and may prompt further medical exploration or the initiation of a treatment plan. While results that exceed normal parameters are typically not a cause for concern, they should still be reviewed by your healthcare provider to ensure a thorough understanding of your lung health.

By aligning individual spirometry results with the most appropriate reference sets, Medikro Spirometry software simplifies the complexity of personalized assessments. This not only ensures precision but also streamlines the process, enhancing the overall quality of respiratory care. In essence, it embodies our ethos: ‘Spirometry Simplified’ — making an intricate process more accessible and accurate for both practitioners and patients.

Factors influencing spirometry test results

Several factors can affect the accuracy of your spirometry test results:

• Test technique and effort: proper technique and maximal effort are essential for reliable results.
• Health conditions: temporary health issues like respiratory infections can impact your test outcomes.
• Environmental Factors: exposure to pollutants or allergens before testing can alter results.

FAQs on Interpreting Spirometry Results

• Can spirometry test results improve over time? Yes, with appropriate treatment ⁸ and lifestyle changes ⁹, your lung function can improve, reflected in future spirometry tests.
• What should I do if my results indicate a problem? Discuss your results with your healthcare provider to understand the implications and next steps, including potential further testing or treatment adjustments.
• How can I ensure accurate spirometry test results? Follow pre-test instructions carefully, ensure you’re in good health at the time of testing, and perform the test with maximal effort.

Conclusion

Interpreting spirometry test results is a nuanced process that requires considering the entire clinical picture, including symptoms, medical history, and other diagnostic tests. It’s essential to have an open and informed discussion with your healthcare provider about what your spirometry test results mean for your health.

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