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Fractional Exhaled Nitric Oxide (FeNO) in Asthma

Fractional Exhaled Nitric Oxide (FeNO) is a pulmonary marker reported as elevated in Asthma when patients are compared with the reference group of the cited comparison (type 2 asthma vs healthy/non-asthmatic individuals). The source does not tie this marker to a specific symptom cluster, so it is best read as a biological signal rather than a symptom predictor. This entry summarises Loewenthal et al. 2022. Group-level associations like this do not translate into an individual diagnostic cut-off.

↑ ElevatedPulmonary

Summary

Direction in Asthma↑ Elevated — higher than in the comparison group
CategoryPulmonary
Compared againsttype 2 asthma vs healthy/non-asthmatic individuals
SourceLoewenthal et al. 2022 — doi:10.1055/s-0042-1743290
Condition atlasAsthma Biomarker Atlas

Related Pulmonary markers in Asthma

Full list: Asthma Biomarker Atlas.

Frequently asked questions

Is Fractional Exhaled Nitric Oxide (FeNO) high or low in Asthma?

Elevated. Studies summarised in the OSMF atlas report higher Fractional Exhaled Nitric Oxide (FeNO) in Asthma than in the reference group of the cited comparison (type 2 asthma vs healthy/non-asthmatic individuals). Source: Loewenthal et al. 2022.

Which test measures Fractional Exhaled Nitric Oxide (FeNO)?

The atlas record does not list a standardised clinical test code (LOINC) for Fractional Exhaled Nitric Oxide (FeNO), which usually means it was measured with research assays or study-specific protocols rather than a routine clinical panel. Check the cited source for the exact method.

Is one abnormal Fractional Exhaled Nitric Oxide (FeNO) result diagnostic of Asthma?

No. No single biomarker is diagnostic of Asthma. Fractional Exhaled Nitric Oxide (FeNO) findings come from group comparisons, overlap considerably between patients and controls, and vary with study design, timing and comparison group. A result should be interpreted by a clinician alongside symptoms, history and other tests.

Cite this page

Open Source Medicine Foundation. (2026). Fractional Exhaled Nitric Oxide (FeNO) in Asthma: direction, evidence and what it means. OSMF Research Tracker. Retrieved October 7, 2026, from https://research.opensourcemed.info/biomarkers/asthma/fractional-exhaled-nitric-oxide-feno.html
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Last reviewed: 2026-07-02 · Page generated from asthma.json · Browse: Asthma atlas · Biomarker Index · All marker pages

Disclaimer: This page is an educational synthesis of published, peer-reviewed research and is not medical advice. Biomarker findings vary across studies with case definitions, comparison groups, timing and assay methods. Direction of change reflects the predominant finding in the cited source and does not establish a diagnostic threshold. Discuss any test result with a qualified clinician.