Lung Testing

Lung Function tests (also called Pulmonary Function Tests or PFTs) are a group of non-invasive tests that measure different aspects of how your lungs work. We test the size of your lungs, the size of your airways and the efficiency of the lungs.

Your testing may include some or all of the following:

FeNO (Fraction Exhaled Nitric Oxide)

This test takes a sample of your breath and lets us see how inflamed your airways are. This is an excellent test to diagnose or rule out an asthmatic component.

Why it matters

This test measures the amount of Nitric Oxide in the airways – the higher the number, the more inflammation there is. This is an excellent test to diagnose eosinophilic asthma.

What happens

You will be asked to blow into a handheld device steadily for 6-10 seconds.

Spirometry

Spirometry is one of the most common and important Lung Function tests. It measures both the size of the lungs and the size of the airways.

Why it matters

This lets us test to see if there are any signs of obstruction or restriction, key factors in diagnosing or ruling out asthma, COPD or other common lung issues.

What happens

You will be asked to take a deep breath and blow out forcefully into a mouthpiece connected to a machine. It is quick, simple, and completely safe.

Gas Transfer Testing (TLCO or DLCO)

Gas Transfer testing measures how well oxygen is delivered into the blood from your lungs.

Why it matters

This test is especially useful in evaluating conditions that affect the lung tissue, such as pulmonary fibrosis, emphysema, or pulmonary hypertension.

What happens

You will be asked to inhale a harmless gas mixture, hold your breath for a few seconds, and then exhale. The test analyses how much gas your lungs absorbed.

Static Lung Volumes (Body Plethysmography)

Static lung volumes measure the size of your lungs more accurately than other tests. This allows us to see your total lung capacity, consisting of your vital capacity and residual volume (the amount of gas left in the lungs when you have exhaled fully).

Why it matters

It helps distinguish between different types of lung problems – whether your lungs are restricted (as in fibrosis) or if there are any signs of hyperinflation or gas trapping (COPD/Asthma).

What happens

You will sit in an enclosed booth similar to a glass cabin and breathe through a mouthpiece while we record pressure and volume changes. The test is safe and comfortable, and the booth is transparent to avoid feelings of claustrophobia. There is also a button inside that can open the door if you are feeling uncomfortable.

Reversibility Testing

Reversibility testing looks at how your airways respond to inhalers – usually the blue inhaler Salbutamol/Ventolin.

Why it matters

This test helps differentiate between Asthma and COPD, and determines how much your airway obstruction can improve with treatment. This will also help your doctor assess how well your current inhalers are working, and whether an inhaler review is required.

What happens

We will perform a baseline Spirometry test and then give you a bronchodilator to inhale (usually salbutamol). After 15 minutes, we repeat the Spirometry to see if there’s a change in your airways.

What to Expect

How to be referred

Duration: Most lung function testing takes 45–60 minutes.
Preparation: Avoid smoking, caffeine, and strenuous exercise for a few hours before your appointment. If possible, avoid using inhalers beforehand unless needed to complete the test.
Comfort: We take extra time to guide you through each test, and our physiologists provide clear coaching throughout.
Afterwards: You can resume normal activities immediately.

Results

Your results will be reported on the same day as your visit and will be sent to your consultant approximately 30 minutes after the appointment.

GP or Other Healthcare Professional:

If your GP or other healthcare professional wishes to refer you to us, they can do this by sending us a referral letter or by using our Diagnostic referral form here. The completed referral form or letter should be sent securely to info@heartsure.co.uk so that we can offer you an appointment.

Please indicate to your doctor if you will be funding this care yourself or if you wish to utilise any Private Health Insurance. Please read below for more information.

Self Referral:

If you wish to have an appointment for a diagnostic test but you have not been referred by your GP or someone else, you can get in touch and refer yourself to us using the Patient Self Referral form here or simply by contacting a member of our team.

If you have any symptoms, past diagnoses, family history or other information that you wish to tell us about, please fill this in as it will help us to arrange the best possible appointment for you. If you wish to use private health insurance to cover the costs of your care, your insurer may not cover your care unless you are referred by a healthcare professional, and so it is advised to confirm this with your insurance provider prior to referring yourself.

Covering your care

Heartsure offers some of the most competitive prices for the area. Please read below about the options of cover that you have available either through health insurance or funding your own care, and the costs associated.

Private Health Insurance:

Heartsure accepts patients from all major UK insurance companies. If you are wishing to use your health insurance policy to cover the cost of your diagnostic tests at Heartsure, please check with your policy to ensure you are covered. Alternatively you can contact your insurance company for more information. A list of all insurance companies that we are registered with can be found here.

If you cannot find your insurance provider on the list above, please contact us. Please note, failure to confirm your care with your insurance company and obtaining an authorisation code could result in the costs of any appointments not being covered. In these circumstances, it remains your responsibility to make payments for any appointments or services that have been completed. For more information, please go to our Private Health Insurance page which you can find here.

Self Funding:

Heartsure makes it easy for you to pay for any services that you have undertaken. We offer the following payment methods:

• Card - we accept all major card providers and are able to take card payments at the clinic if you wish.

• Bank Transfer - all of our bank details are provided on our invoices. If you require any further information, please contact us.

• Online payments - we are able to facilitate easy online payments through iZettle. We will attach a payment link to each invoice, and you are welcome to use this as a safe and secure way to pay

If you wish to self-fund your care, or someone is covering your care for you, you/they must complete our 'Fees and Insurance' form to confirm a commitment to pay the full fees. Our fee schedule can be found here, which should be used only if you are 'self-funding'. For more information about Self-Funding, please find our Self-Funding page which can be found here. For those patients who have health insurance, please see the information above.

More information:

For more information about Lung Testing, you can find a detailed guide about Ambulatory Monitoring here.