label: Elevated fraction exhaled nitric oxide
label_lc: elevated fraction exhaled nitric oxide
description: The fractional exhaled nitric oxide (FeNO) is elevated above the upper limit of normal. FeNO is an endogenous gaseous molecule which can be measured in the human breath test because of airway inflammation. It has been studied extensively as a marker of inflammation and has been incorporated into an algorithm for asthma management.