Accurate asthma diagnosis is essential for effective treatment and management. The FeNO (Fractional Exhaled Nitric Oxide) test is a non-invasive method used to measure airway inflammation and assess conditions like asthma. This test helps doctors evaluate the severity of inflammation and determine the best course of treatment.
This article covers everything you need to know about the FeNO test, including its purpose, procedure, benefits, accuracy, and how it aids in asthma management.
What Is the FeNO Test?
The Fractional Exhaled Nitric Oxide (FeNO) test measures the amount of nitric oxide (NO) in a patient’s breath. Nitric oxide is produced by cells in the airways, and increased levels indicate inflammation, commonly associated with asthma and other respiratory conditions.
This test helps doctors determine whether a patient’s symptoms are due to asthma or other respiratory issues. It is particularly useful for assessing eosinophilic airway inflammation, which is linked to allergic asthma.
Why Is the FeNO Test Important?
The FeNO test is an essential tool in asthma diagnosis and management because:
It helps identify inflammation levels in the airways.
It is a quick, non-invasive, and painless test.
It helps determine whether corticosteroids or other anti-inflammatory medications are needed.
It aids in monitoring the effectiveness of ongoing asthma treatment.
It helps distinguish between asthma and other respiratory conditions like COPD (Chronic Obstructive Pulmonary Disease).
Who Should Get a FeNO Test?
Your doctor may recommend a FeNO test if:
You have symptoms such as wheezing, coughing, shortness of breath, or chest tightness.
Your asthma symptoms are not well-controlled, despite medication.
There is a need to monitor inflammation levels during treatment.
Other lung function tests (like spirometry) have provided inconclusive results.
How Is the FeNO Test Performed?
The FeNO test is simple and takes only 5 to 10 minutes. Here’s how it works:
Step-by-Step Procedure
Preparation: The patient sits in a comfortable position and takes a deep breath in.
Breath Exhalation: The patient exhales slowly and steadily into a handheld device through a mouthpiece.
Measurement: The device measures the concentration of nitric oxide in the breath.
Results: The results are usually available immediately and help the doctor assess the level of airway inflammation.
Understanding FeNO Test Results
FeNO levels are measured in parts per billion (ppb), and the results are categorized as follows:
Low FeNO Levels (<25 ppb in adults, <20 ppb in children): Indicates minimal airway inflammation. Asthma is less likely.
Intermediate FeNO Levels (25–50 ppb in adults, 20–35 ppb in children): Suggests possible inflammation. Further tests may be needed.
High FeNO Levels (>50 ppb in adults, >35 ppb in children): Indicates significant airway inflammation, which is often linked to asthma.
High FeNO levels suggest that anti-inflammatory medication, such as corticosteroids, may be required for effective asthma management.
Benefits of the FeNO Test
The FeNO test has several advantages over other diagnostic methods:
Non-invasive: No needles or invasive procedures are required.
Quick Results: The test is completed in a few minutes, and results are available immediately.
Effective Asthma Management: Helps determine the need for corticosteroid medication.
Monitoring Treatment: Tracks the effectiveness of asthma treatment over time.
Better Accuracy: More effective than traditional lung function tests in diagnosing allergic asthma.
FeNO Test vs. Spirometry: What’s the Difference?
While spirometry is a common lung function test for asthma diagnosis, it primarily measures airflow obstruction rather than inflammation. The FeNO test is more specific for detecting airway inflammation, particularly in cases of eosinophilic asthma.
For a comprehensive asthma diagnosis, doctors may recommend both spirometry and FeNO testing.
Limitations of the FeNO Test
While the FeNO test is highly effective, it does have some limitations:
It is not a standalone test; other lung function tests may be needed.
Factors like diet, smoking, and respiratory infections can affect FeNO levels.
It is most useful for diagnosing eosinophilic inflammation but may not be as effective for other types of asthma.
How to Prepare for a FeNO Test
To get accurate FeNO test results, patients should:
Avoid eating or drinking (except water) at least one hour before the test.
Refrain from smoking at least two hours before the test.
Avoid strenuous exercise on the day of the test.
Inform the doctor about current medications (as some may influence FeNO levels).
Conclusion
The FeNO test is a valuable tool for diagnosing and managing asthma by measuring airway inflammation. It is quick, non-invasive, and provides real-time insights into respiratory health.
If you experience asthma symptoms or want to monitor your treatment progress, consult a healthcare provider about getting a FeNO test. Early diagnosis and proper management can significantly improve your respiratory health.
Book a FeNO Test Today
If you need an accurate assessment of your airway inflammation, consider scheduling a FeNO test with a trusted healthcare provider. Early detection and proper treatment can help you breathe better and live healthier.
For more information about asthma management and health checkups, visit Mediwheel.
