From: Using fractional exhaled nitric oxide (FeNO) to diagnose steroid-responsive disease and guide asthma management in routine care
Adults/Adolescents (Ages 12 and older)
Children (Ages 4–11)
Low/normal (ppb)
<25
<20
Intermediate (ppb)
≥25 and ≤50
≥20 and ≤35
High (ppb)
>50
>35