FeNO result of 39

[AirIsUnderrated]

I have not got an asthma diagnosis, but had inhalers (salbutamol, Clenil, Fostair) for 18 months after suspected Covid in March 2020. I stopped using them after I stopped noticing a benefit, and by then I had a breast cancer diagnosis so I had more to worry about. My breathing seemed fine other than a permanent, nasty itch in my right lung that feels like a mosquito bite in there. That level of itch, you know?

With the cancer, my lungs dropped to the bottom of my list of priorities. When I had surgery in July for the second cancer (womb), the anaesthetist asked about my breathing, so I told her about it. The oncologist then got me referred for FeNO and spirometry for the first time since Covid began.

I had my FeNO test this morning, not expecting anything to show up because it's only an itch, right? I scored 39. The nurse said that means I have inflammation. I'm in the UK, where FeNO results have a different range from the US. My spirometry is next week.

Can anyone give me the benefit of their own FeNO results experience? Thank you so much.

[Homely2 Administrator]

I had 45 twice at a specialist hospital in the autumn. They said this was indicative of asthma and with a peakflow history diagnosed asthma

I had a feno reading of 38 in the spring at my local general hospital, just a week after coming off prednisone. My consultant said this was indicative of inflammation, but as it was less than 40 it was not indicative of asthma. However I do not really trust this consultants asthma knowledge, as the NHS regulations says that the 40 limit is for people not on steroids.

[Chip_y2kuk]

15 or under is normal ... at 39 you definitely have "some inflammation" .... but I know that 30 odd is classes as "intermittent inflammation" and the numbers go higher

[Nanto4]

Thats a good reading , my consultant said has to be 40 or below , mine was 130 so i have been referred and on waiting list for biologics .

[AirIsUnderrated in reply to Nanto4]

Is it a good reading if I'm not asthmatic though? I just don't know the ranges or implications.

[flowerjunky]

mine was 225 at diagnosis (I could barely breathe !). 2 years later and despite high dose inhalers and various other meds I’m still at 77.

FeNo is just one of the tests used to confirm a diagnosis of asthma along with spirometry and symptoms. Hopefully your spirometry next week will help give your consultant a clearer picture what is going on.

[gemwatercolour]

I don’t feel asthmatic at all but was hospitalised earlier this year with very high blood eosinophil levels (1.9), breathing difficulties and pneumonia. I have an excellent consultant who is very well published in the field of asthma. I’m taking a relatively high dose of Fostair. After a rough couple of months, my breathing stabilised and I’ve had no problems at all since end of March. I’ve had spirometry and have excellent lung function, at the top end for my age, weight and sex, and I hoped the consultant would say I could reduce my meds. However, FENO was 59 despite being on a steroid inhaler so he said he was actually considering increasing the dose! Given lung function is stable, he wants me to carry on with the dose I’m at pending next review in January.

I know people can have much higher FENO levels, but I’ve had no symptoms at all with that level of inflammation since March

[Lysistrata Administrator Community Ambassador]

My FENO is all over the place. I either seem to score 16-18 (which in some ranges is considered normal) or mid-30s which my asthma team who are obsessed with FENO say is 'not bad for asthma but worth noting, especially if you're already being treated' (I got it once while on loads of steroids and am permanently on high dose inhaled steroids). The range I've seen is under 25 normal, 25-49 'intermediate' and 50 plus 'high' but that is one range. My type of asthma mostly doesn't seem to be driven by the inflammation that FENO measures though (it's one type of inflammation).

As flowerjunky has said, it's just one part of the puzzle - your spirometry/peak flow/symptoms and history all need to be included because FENO by itself shouldn't be used to rule asthma in or out.

I personally do not find FENO very helpful BUT I'm aware it can be for others and has its place. It doesn't necessarily match up neatly with symptoms even when it is showing inflammation - but then inflammation itself in asthma isn't necessarily associated with symptoms, as you can have one without the other.

I'm not saying this is you, as this isn't the place to diagnose, but hayfever/atopic nasal issues can also increase FENO as it doesn't tell you exactly where the inflammation is. Some foods like spinach can also affect the reading, and being male and/or taller than average can affect it (I can't remember which way now).