The WWL Way
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Lung Function Test

The lung function test is designed to find out what is happening in your lungs.

The different tests you will perform during your appointment will look primarily at how well you can breathe in and out and how well your lungs are performing. Please ensure you have a copy of your current medication to hand.

A Clinical Physiologist or assistant will be performing the test.

What to Expect

There are three different types of test.


This test can diagnose many lung conditions, most commonly COPD (Chronic Obstructive Pulmonary Disease).
Spirometry can also monitor the severity of various lung conditions and how well they are responding to treatment.

During the Test:

  • You will be asked to take a large breath in and then blow out as fast as you can until your lungs are completely empty
  • You will then need to take a large breath in to complete the test
  • A clip will be placed on your nose during all the lung function tests to ensure that no air escapes from your nose
  • This test will be done three times in total

Reversibility Test

If you have already been prescribed short acting reliever inhaler, please stop taking this for four hours prior to the test. If this is not possible, please inform the Physiologist that you have taken it and at what time.
Do not stop taking any prescribed oral or inhaled steroid medication for this test.

During the Test:

  • The test will begin with the basic Spirometry Test
  • The Physiologist will then administer a nebuliser or a bronchodilator called Salbutamol
  • This lasts for around three - five minutes
  • After this, the Spirometry Test will be repeated to see if the lung capacity has improved
  • The medication should stimulate the airways in the lungs to dilate and improve airflow

Gas Transfer Test

This test is used to show how well your lungs can perform their main function of getting oxgen into your bloodstream and carbon dioxide out.

During the Test:

  • You will be asked to take a big breath through the mouth piece of the testing equipment
  • You will then need to hold your breath for a few seconds before breathing back out into the mouth piece

Lung Volume Test

The test is usually performed in a booth whilst the door is closed.

It will determine how much air is in your lungs and how much is left when you breathe out all the air you can manage.

Patients who have COPD may have a higher volume of air left in the lungs than a person with normal lungs.

This test will allow the doctor to know more about the lung disease (if any) and the best way of treating the problem.

The test requires you to breathe into a machine as instructed by a Cardiac Clinical Physiologist. It will take around 30 minutes to perform.