Concierge respiratory · London
Private FeNO asthma test in London, a 60-second breath test that changed asthma diagnosis.
A quick, non-invasive breath test that measures airway inflammation — central to modern NICE asthma diagnosis and to picking biologic-eligible patients.
Why patients choose us
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The right test, not the quick one
We match FeNO to the question — diagnosis, phenotyping or biologic-eligibility — and pair it with spirometry when it earns its place.
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Read by a respiratory physician
A consultant respiratory physician interprets your FeNO value in the context of your history, inhaler use and spirometry.
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Independent, and free
We are paid by no clinic, so the recommendation is impartial and costs you nothing.
Indicative pricing
What a private FeNO asthma test costs in London.
Indicative ranges across our partner clinics. Send the details and we quote firm figures across two or three options.
In short
FeNO alone: £75–£150; a full asthma diagnostic bundle: £450–£900.
| Test | Indicative range | Typical duration | Report turnaround |
|---|---|---|---|
| FeNO only | £75–£150 | 10 min | Same visit |
| FeNO + spirometry | £180–£350 | 30 min | Same visit |
| FeNO + full PFTs | £400–£800 | 60 min | Same visit |
| FeNO + respiratory consult | £280–£550 | 60 min | Same visit |
| Full asthma diagnostic bundle | £450–£900 | 60 min | Same visit |
| Post-biologic FeNO monitoring | £75–£150 | 10 min | Same visit |
Prices vary by clinic, which studies are included, and whether a consultant review is arranged on the day. We come back with a firm quote within one working day.
The problem
Asthma is one label for several different diseases.
FeNO separates eosinophilic, steroid-responsive asthma from the rest — quickly, cheaply and at the mouthpiece. Pairing it with spirometry is now the modern NICE-standard first step, and it is the fastest way to know who will respond to biologics.
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Suspected but never confirmed asthma?
FeNO plus spirometry with reversibility is the definitive modern workup — in a single visit.
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Poorly controlled on inhalers?
A rising FeNO on treatment points to adherence, technique or dose — a fixable problem.
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Considering a biologic?
FeNO is one of the fastest markers used to screen for anti-IL-4/13 and anti-IgE eligibility.
The journey
From enquiry to report — what happens, in order.
One clinician from first message to explained result — often within a single visit for FeNO alone.
Phase 1 · Before your test
Concierge, off-stage for you
Phase 2 · On the day
10–60 minutes at the clinic
Phase 3 · After
Concierge, back on
- 01
Before
You tell us what is going on
A short, confidential form. Symptoms, timeline, referral or insurer if you have them.
- 02
Before
We come back with a recommendation
Within one working day: which test, which clinic, indicative price. If a test is not the right step, we say so.
- 03
Before
We arrange the appointment
Often same or next day, including evenings and Saturdays. Insurer pre-authorisation handled.
- 04
On the day
Arrival and preparation
You sit upright and are shown how to breathe steadily through the FeNO analyser mouthpiece.
- 05
On the day
The test
A single steady 10-second exhalation gives a FeNO value in under 60 seconds. Two or three passes are averaged.
- 06
On the day
Straight home
No recovery time. Drive, eat and work as normal.
- 07
After
Report and next steps
Consultant respiratory physician report the same visit or within 24 hours, with onward referral where needed.
Typical end-to-end: 1–2 days. Urgent cases: same day.
What it shows
Find the test that matches your indication.
FeNO answers a narrow but important set of questions in asthma care. These are the ones we are asked most.
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Confirming asthma diagnosis
A raised FeNO with compatible symptoms strongly supports an asthma diagnosis alongside spirometry.
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Eosinophilic asthma phenotype
FeNO is the fastest bedside marker of type-2, eosinophil-driven airway inflammation.
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Biologic-eligibility screen
A high FeNO helps identify patients likely to respond to anti-IL-4/13 and anti-IgE biologics.
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Uncontrolled asthma
A rising FeNO on treatment suggests poor adherence, wrong device or steroid under-dosing.
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Paediatric asthma diagnosis
FeNO is validated in children old enough to perform a steady 10-second exhalation.
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Pre-op asthma clearance
A quick objective marker of airway inflammation before elective anaesthesia.
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Monitoring inhaled steroid response
FeNO falls within days of an effective inhaled corticosteroid — a useful control check.
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Red flags
Acute breathlessness, silent chest, blue lips or collapse is an emergency — call 999.
FeNO options
Not all FeNO appointments are the same.
What each option on your referral is actually for.
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FeNO only
The standalone 60-second breath test — quick, cheap and often enough to move a diagnosis forward.
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FeNO + spirometry
The NICE-recommended pairing for suspected asthma: inflammation plus airflow in one visit.
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FeNO + full PFTs
Adds lung volumes and gas transfer when restrictive or overlap disease is on the differential.
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FeNO + respiratory consult
FeNO measured on the day, then interpreted face-to-face with a consultant respiratory physician.
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Full asthma diagnostic bundle
FeNO, spirometry with reversibility and consultant review — the definitive workup in a single visit.
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Post-biologic monitoring
Serial FeNO to track response to mepolizumab, benralizumab, dupilumab or omalizumab.
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Occupational asthma pathway
Baseline and serial FeNO around work exposure — useful when workplace triggers are suspected.
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Paediatric FeNO (specialist)
Delivered by clinicians experienced in coaching children through a reliable exhalation.
Our vetted London network
A small panel of clinics, we picked them.
Partners across central, north, west and south London. Not listed publicly — introductions are made privately, once we understand your case.
Selection criteria
How we choose every clinic in our network.
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Consultant respiratory physicians
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Calibrated FeNO analysers
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ATS/ERS FeNO standards
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Biologic-therapy referral pathway
Safety and eligibility
Painless, non-invasive — and prep is minimal.
FeNO is one of the safest tests in respiratory medicine. A short fast, no vigorous exercise and no smoking beforehand is usually all that is asked.
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1-hour fast before test
Nothing to eat for one hour before the appointment so recent food does not skew the reading.
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Avoid exercise 1 hour before
Vigorous exertion transiently lowers exhaled nitric oxide. Rest quietly for an hour beforehand.
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Avoid smoking or vaping 1 hour before
Smoke and vapour lower FeNO acutely. Please avoid both for at least an hour before the test.
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Not affected by pregnancy
FeNO is a passive breath test and is entirely safe at any stage of pregnancy.
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A single elevated FeNO is meaningful
In the right clinical context, one raised value is enough to change management — no repeat is required.
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Steroids reduce FeNO
Recent inhaled or oral corticosteroids can lower the reading — we record what you have taken and when.
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Nitrate-rich foods can transiently raise it
Spinach, beetroot and processed meats can nudge FeNO upward for a few hours after eating.
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Asthma diagnosis needs more than one test
FeNO + spirometry (and reversibility where needed) — no single test alone confirms asthma.
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Always share prior asthma tests
Old FeNO, spirometry and peak-flow diaries let us plot a trend rather than judge a single number.
Reading your report
A FeNO report looks like one number. Context is everything.
Whether alone or paired with spirometry, the report keeps to the same four parts.
A quiet reminder
A single elevated FeNO is meaningful — but only in the right clinical context.
If you would like us to talk you through it before your follow-up, just ask.
- 01 Header
Your details, indication and medications
Your details, the reason for testing and every inhaler or steroid you have taken in the last 4 weeks.
- 02 Technique
Device and technique
Which analyser was used, calibration status, and whether the exhalation met ATS/ERS acceptability.
- 03 Findings
FeNO value and interpretation
Your ppb value plotted against the < 25 / 25–50 / > 50 thresholds used in modern asthma guidelines.
- 04 Impression
The conclusion: read this first
Likely eosinophilic asthma, unlikely, or intermediate — with the recommended next step. Read this first.
Recognised by major UK insurers
Cover depends on your policy and clinic; we confirm with your insurer before booking.
Frequently asked
Everything we get asked about FeNO asthma testing.
Quick answers on cost, referrals, fasting, steroids and results.
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What does a FeNO test actually measure?
FeNO measures the concentration of nitric oxide in your exhaled breath, reported in parts per billion (ppb). Nitric oxide is produced by inflamed airway cells in type-2, eosinophilic inflammation — the pattern most closely linked to allergic and steroid-responsive asthma.
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Do I need to fast before a FeNO test?
Yes — a light one-hour fast is recommended. Nitrate-rich foods such as spinach, beetroot and processed meats can transiently raise FeNO, so avoiding food for an hour beforehand gives the cleanest reading.
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Is FeNO safe in pregnancy?
Completely. FeNO is a passive breath test with no radiation, no injections and no medication. It can be performed at any stage of pregnancy and is often useful for reviewing asthma control before delivery.
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Can children have a FeNO test?
Yes — FeNO is validated in children who are old enough to perform a steady 10-second exhalation, typically from around age 6. We route paediatric cases to clinicians experienced in coaching younger patients through the manoeuvre.
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How does FeNO fit into an asthma diagnosis?
Modern guidelines (NICE NG245, BTS/SIGN, GINA) recommend combining FeNO with spirometry — and bronchodilator reversibility where appropriate. A raised FeNO plus obstructive spirometry with reversibility is the most robust confirmation of asthma.
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How much does a private FeNO test cost in London?
A standalone FeNO is typically £75–£150. Paired with spirometry it is £180–£350; with full PFTs £400–£800; and inside a full asthma diagnostic bundle with a consultant review £450–£900. We confirm a firm figure within one working day.
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Do I need a referral?
No — most clinics in our network accept self-referral for FeNO. We can arrange a fast-track private GP or respiratory physician if you would like the result interpreted in a consultation.
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How quickly do I get the results?
The FeNO value is available immediately at the mouthpiece. A written interpretation from a consultant respiratory physician follows the same visit or within 24 hours.
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How do steroids affect FeNO?
Inhaled and oral corticosteroids suppress eosinophilic airway inflammation and therefore lower FeNO — often within days. That is diagnostically useful: a falling FeNO on treatment suggests you are responding well to your inhaled steroid.
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When should I see a GP or 999 urgently?
FeNO is not for emergencies. If you have acute severe breathlessness, chest pain, blue lips, a silent chest or collapse, call 999. Rapidly worsening asthma control between appointments warrants an urgent GP or A&E review.
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