A FeNO test or exhaled nitric oxide test, in patients with allergic or eosinophilic asthma, is a way to determine how much lung inflammation is present and how well inhaled steroids are suppressing this inflammation. With allergic or eosinophilic asthma, sometimes you may feel your breathing is fine, but when you measure your exhaled nitric oxide, it may still be significantly elevated, and you might do better in the long-term using slightly more of your inhaled steroid to suppress this inflammation.
Nitric oxide is a gas produced by cells involved in the inflammation associated with allergic or eosinophilic asthma.
Asthma begins with inflammation. The lining of the airways becomes swollen, inflamed and clogged with mucus and fluid.
Asthma inflammation is the quiet part of asthma. When we talk about quiet asthma, that’s when the inflammation and swelling takes place. You can’t feel or see what’s going on, but each time your airways are exposed to your asthma triggers, the inflammation may increase, and your symptoms may get worse.
High FeNO levels indicate your airways are inflamed or irritated. This is why FeNO testing is a valuable tool in testing for asthma.
While an elevated FeNO test does not confirm a diagnosis of asthma, it does indicate that you may be experiencing airway inflammation or irritation. This, along with your medical history, physical exam and other tests, should help your doctor determine if you have asthma.
In clinical practice, a normal FeNO test is any number less than 25 parts per billion (ppb) in adults. For children, anything less than 20 ppb is considered normal.
You may be asking, what causes a high FeNO? Just because you have an elevated FeNO does not necessarily mean you have asthma. What it does suggest is that you may be experiencing some level of airway inflammation. And airway inflammation is often an indicator of asthma.
Your healthcare provider will want to look at your symptoms, history, and other tests for asthma to make a diagnosis.
A FeNO of 25-50 ppb in adults (20-35 ppb in children) is considered an intermediate range. Numbers in this range should be matched with the medical history and testing. FeNO numbers of over 50 ppb in adults (over 35 ppb in children) are considered high and indicate airway inflammation.
FeNO testing is also a helpful tool in ongoing asthma management. Patients with well-controlled asthma typically have lower levels of exhaled nitric oxide. While patients with uncontrolled asthma may have a number of over 30 ppb, FeNO levels may also be elevated during asthma exacerbations.
We have facility of FeNO Test Lab at:
Haridaya Superspeciality Centre
Dr. Ahish Tandon
16/28, Stanley Road, Civil Lines,
Near Police Line Helicopter Landing Site,
Allahabad, Uttar Pradesh 211001,India
+91 9792456999, +91 9336281819, +91 8004915141
info@chestspecialistallahabad.com
