Service

FENO Test

FeNO (Fractional exhaled Nitric Oxide) is a quick, painless breath test that measures nitric oxide in your breath — a marker of the allergic airway inflammation seen in asthma. It adds an objective number to the picture, helping us confirm asthma, choose the right inhaler and check whether treatment is genuinely controlling the inflammation.

What it tells us

Whether allergic (eosinophilic) airway inflammation is present
How likely inhaled steroids are to help
Whether your current treatment is controlling the inflammation
Whether the preventer inhaler is being taken as prescribed

What to expect

You breathe out slowly and steadily into a handheld device for about ten seconds. It is completely painless, takes only a few minutes and gives a result on the spot.

Getting ready

Avoid eating, drinking or exercising just before the test
Tell us about recent steroid use or a current cold
Continue your usual medicines unless we advise otherwise