Concierge respiratory physiology · London
Lung volume tests, body plethysmography and helium dilution to measure TLC, RV and FRC.
Lung volume tests measure Total Lung Capacity (TLC), Residual Volume (RV), Functional Residual Capacity (FRC) and their ratios. Distinguishes restrictive from obstructive lung disease and quantifies gas trapping in emphysema — using body plethysmography or helium dilution.
Why patients choose us
- 01
The right hands
We route you to a consultant respiratory physician — with lung volume testing, the physiologist who measures you and the consultant who reads it decide the answer.
- 02
Often answers same-day
Findings can frequently be discussed immediately, with the written report to follow.
- 03
Independent, and free
We are paid by no clinic, so the recommendation is impartial and costs you nothing.
Key facts
The six things worth knowing about lung volume tests.
What lung volume testing measures, how it’s done, and what a good result looks like.
-
Definition
Measurement of Total Lung Capacity (TLC), Residual Volume (RV) and Functional Residual Capacity (FRC) via body plethysmography or helium dilution.
-
You sit in a body box
For plethysmography, you sit inside a sealed cabin (the body box) and breathe against a shutter.
-
Complements spirometry
Adds the static volumes that spirometry and gas transfer cannot measure directly.
-
Restrictive vs obstructive
A reduced TLC signals a restrictive pattern; a raised TLC and RV signal obstruction with hyperinflation.
-
Quantifies gas trapping
The RV/TLC ratio quantifies gas trapping in emphysema and chronic airway disease.
-
Reported per GLI reference
Values are reported with Global Lung Function Initiative (GLI) reference equations and Z-scores.
How it works
From referral to report — what happens, in order.
One consultant respiratory physician and one physiologist from first referral to report — usually within days.
Phase 1 · Before your test
Referral and preparation
Phase 2 · On the day
~45 minutes at the lab
Phase 3 · After
Report and plan
- 01
Before
Respiratory referral
A consultant respiratory physician or GP refers you, defining the question the test needs to answer.
- 02
Before
Withhold bronchodilators
If requested, short and long-acting inhalers are paused for a defined window before the test.
- 03
Before
Baseline spirometry
Spirometry is performed first, on the same visit, to anchor the flow-volume picture.
- 04
On the day
Body-box or helium-dilution rig
You either sit in the sealed body plethysmograph or breathe into a closed helium-dilution circuit.
- 05
On the day
Multiple manoeuvres
Several breathing manoeuvres are repeated until acceptability and repeatability criteria are met.
- 06
On the day
TLC, RV, FRC calculated
The physiologist calculates TLC, RV, FRC and the RV/TLC ratio from the recorded traces.
- 07
After
Report with GLI Z-scores
The consultant issues a report against Global Lung Function Initiative reference values, with Z-scores.
Typical end-to-end: 3–7 days. Urgent cases: same week.
What it shows
When lung volume testing is the right test.
Lung volume tests answer a specific question — is the underlying physiology restrictive or obstructive, and how much gas is being trapped. These are the presentations we see most.
-
Restrictive lung disease
A reduced Total Lung Capacity is the defining physiology of restriction — ILD, chest-wall or neuromuscular disease.
-
Hyperinflation
Raised TLC and RV point to hyperinflation in COPD, asthma and emphysema.
-
Gas trapping (RV/TLC)
The RV/TLC ratio quantifies air that cannot be exhaled — a marker of small-airways disease.
-
Response to bronchodilator
Change in RV after bronchodilator is a sensitive marker of small-airway response.
-
Response to volume-reduction surgery
Assesses gain in usable lung after lung-volume-reduction surgery or endobronchial valves.
-
Baseline before biologic therapy
Baseline lung volumes before starting biologics for severe asthma or eosinophilic disease.
-
Fitness for lung resection
Contributes to pre-operative risk assessment before lobectomy or pneumonectomy.
-
Red flag: severe restrictive pattern + hypoxia — respiratory MDT
A severe restrictive pattern with resting hypoxia is a same-week respiratory-MDT referral, not routine follow-up.
Test types
Not all lung volume tests are the same.
What each option on your referral is actually for.
-
Body plethysmography
Gold-standard measurement of TLC, RV and FRC inside a sealed body box.
-
Helium dilution
Closed-circuit inert-gas dilution — an alternative when plethysmography isn’t tolerated.
-
Nitrogen washout
Multiple-breath nitrogen washout, an equivalent open-circuit gas-dilution technique.
-
Pre/post-bronchodilator volumes
Repeat measurements after a bronchodilator to quantify small-airway response.
-
Volumes + gas transfer (TLCO)
Paired with a diffusing-capacity (TLCO/DLCO) measurement on the same visit.
-
Volumes + spirometry package
Full lung-function package: spirometry, static volumes and gas transfer.
-
Pre-operative lung-function panel
The extended panel used before lung resection or major thoracic surgery.
-
Urgent same-week slot
Expedited slot when symptoms or a referral demand a rapid answer.
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 lab in our network.
-
Consultant respiratory physicians with accredited lung-function physiologists
-
ERS/ATS technical standards for static lung volumes
-
GLI (Global Lung Function Initiative) reference equations for reporting
-
Onward respiratory-MDT pathway if significant restrictive or fibrotic disease is found
Safety and eligibility
One of the safest tests in respiratory medicine.
Lung volume testing is exceptionally safe — the practical points are the body box, the inhaler washout and where the test’s limits are.
-
Painless, radiation-free
A mouthpiece and nose clip — no needles, no radiation, no dye.
-
The body box
A clear, well-ventilated cabin. The door is unlocked at all times; you can leave at any point.
-
Claustrophobia
Tell us in advance — the physiologist will talk you through, or we route you to helium dilution instead.
-
No fasting
Eat and drink as normal. Avoid a heavy meal in the hour before.
-
Inhaler washout
If bronchodilators are being withheld, we set out the exact timing before your visit.
-
Chest or abdominal surgery
Recent surgery, unstable angina or recent MI may delay testing — we screen for this at booking.
-
A normal test is not a full clear
Normal static volumes do not exclude airway disease, pulmonary vascular disease or early ILD.
-
CT chest sometimes follow-on
For structural correlation — emphysema pattern, fibrosis or nodules — a CT chest is the next step.
-
Bring prior lung-function reports
Comparison against previous tests materially sharpens the interpretation and the plan.
Red flags — same-week respiratory review
- Severe hyperinflation
- Rapid TLC decline
- Post-COVID lung disease
- Interstitial lung disease
- Alpha-1 antitrypsin
- Post-pneumonectomy
- Neuromuscular restrictive disease
- Chest-wall disease (kyphoscoliosis)
- Respiratory-failure pattern
Treatment options
What follows an abnormal result.
Lung volume tests point to the physiology — the treatment plan is set by the consultant respiratory physician and, where needed, the multidisciplinary team.
-
Inhaled therapy for COPD
Optimised inhaled bronchodilator and steroid therapy per NICE NG115.
-
Anti-fibrotic therapy for IPF
Pirfenidone or nintedanib in idiopathic pulmonary fibrosis, prescribed by the ILD MDT.
-
Lung volume reduction surgery / bronchoscopic valves
Selected emphysema patients benefit from surgical or endobronchial-valve volume reduction.
-
Pulmonary rehabilitation
Structured exercise and education programme with proven survival and quality-of-life benefit.
-
Home NIV for chronic respiratory failure
Domiciliary non-invasive ventilation for chronic hypercapnic respiratory failure.
-
Chest physiotherapy
Airway clearance and inspiratory-muscle training in restrictive and neuromuscular disease.
-
Transplant assessment
Referral to a transplant centre when advanced disease is progressing despite optimal therapy.
-
Structured respiratory follow-up
Serial lung-function testing at defined intervals to track trajectory and adjust therapy.
Reading your report
A lung-function report can look intimidating. It isn’t.
Whatever the finding, the report keeps to the same four parts.
A quiet reminder
The report is written for your doctor, not for you — and that’s normal.
If you would like us to talk you through it before your follow-up, just ask.
- 01 Header
Indication and demographics
Your details, the reason for the test, and the demographic variables (age, height, sex, ethnicity) that shape reference values.
- 02 Technique
Plethysmography or helium dilution
Which technique was used, acceptability and repeatability of the manoeuvres.
- 03 Findings
TLC, RV, FRC and RV/TLC with GLI Z-scores
Static volumes reported against GLI reference values, with Z-scores flagging restriction, hyperinflation or gas trapping.
- 04 Impression
The conclusion: read this first
Normal, restrictive, obstructive-with-hyperinflation, or mixed — and the concrete next step.
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 lung volume tests.
Quick answers on what the test measures, how it differs from spirometry, cost, referrals, claustrophobia and turnaround.
-
What do lung volume tests actually measure?
Static lung volumes — Total Lung Capacity (TLC), Residual Volume (RV) and Functional Residual Capacity (FRC) — and their ratios. Unlike spirometry, which measures air you can move, lung volumes measure the air that stays in your chest at each point of the breathing cycle.
-
What is the difference between body plethysmography and helium dilution?
Body plethysmography measures all the gas in your chest, including gas trapped behind narrowed airways, by pressure changes in a sealed box. Helium dilution only measures the gas that communicates with the airways. In severe emphysema, plethysmography gives a truer TLC.
-
How much does a private lung volume test cost in London?
A full lung-function package (spirometry, static volumes, gas transfer) is typically £250–£500 in our network; a stand-alone lung-volume study is at the lower end. We confirm a firm figure within one working day.
-
Do I need a referral?
Most respiratory laboratories require a referral so the physiologist knows which manoeuvres to prioritise. We can arrange a fast-track private respiratory consultation if you don’t have one.
-
Is the body box claustrophobic?
The cabin is transparent, well-lit and ventilated, and the door is never locked. If you know claustrophobia is an issue, tell us — the physiologist will talk you through, or we route you to helium dilution instead.
-
How quickly will I get results?
The report from the consultant respiratory physician typically arrives within 24–48 hours, with headline findings often discussed on the day.
Sources
- NICE. Chronic obstructive pulmonary disease in over 16s: diagnosis and management (NG115).
- ERS/ATS. Technical standards for lung function testing.
- British Thoracic Society. Guidelines and quality standards.
- Association for Respiratory Technology and Physiology (ARTP).
Reviewed by Pulse Atlas Editorial Board, . Last reviewed 2026-07-30. Next review 2027-07-30. Estimated reading time 5 minutes.
Related tests
Looking for a different test?
-
Lung function test
Spirometry — the first-line airflow measurement.
Learn more -
Gas transfer
TLCO / DLCO — how efficiently the lungs transfer gas to blood.
Learn more -
CPET
Cardiopulmonary exercise testing — integrated heart-and-lung physiology under load.
Learn more -
All tests
Browse every test and procedure we arrange.
Learn more -
Asthma
Related condition guide.
Learn more -
COPD
Related condition guide.
Learn more -
Continuous Positive Airway Pressure
Related treatment option.
Learn more -
Complementary Alternative Medicine
Related treatment option.
Learn more
In practice, in London
The London pathway for lung volume tests
With lung volume tests, the London question is usually about report turnaround and the radiologist reading it — not whether the scan is available. Waiting lists on the NHS for lung volume tests vary widely by borough and by how the GP letter reads. Privately in London, we can normally offer a slot inside the same week, sometimes within 48 hours if there’s a cancellation. The difference isn’t clinical quality — the consultants are frequently the same faces you’d see on the NHS — it’s the calendar.
In practice, a private lung volume tests appointment in London means a named consultant, a proper hour in the room (or the equivalent on a video call), and a report you can actually read. Most of the imaging suites and endoscopy units we use sit within a mile of Harley Street or in Chelsea and Fulham, and turnaround on findings is measured in days, not weeks. For lung volume tests specifically, the difference between a routine report and a sub-speciality read is where private care earns its keep.
We’re careful about what a private pathway for lung volume tests can and can’t promise. It can compress a wait, put you in front of a subspecialist quickly, and get a proper report in your hands within a week. It can’t rewrite what the imaging or the bloods say. Setting that expectation up front tends to make the whole experience less stressful.
Nearby in the library