There are various different tests which are part of a full lung function test. Each of the lung function tests that we ask you to perform during your appointment will be explained to you by a Respiratory Physiologist (a specialist in breathing) and you will perform each test a few times to ensure accuracy. You will be seated for all of the tests. Each different test is explained as follows. You may have been referred for some, or all of these tests.
Spirometry
This test gives us information about how open your airways are, and the size of your lungs. We will ask you to breathe in fully and to perform a relaxed blow out, into a mouthpiece, for as long as you possibly can. This will be done in a seated position with a nose peg on. We will then ask you to breathe in fully and to blow out as hard and as fast as possible into a mouthpiece on the lung function equipment, until you are completely empty.
Reversibility
This test gives information about how your airways are affected by inhaler medication. You will perform spirometry, take an inhaler and then be asked to wait for between 20 and 40 minutes (depending on the type of inhaler medication) before you perform spirometry again.
Transfer Factor
This test measures how efficiently oxygen exchange takes place across your lungs. We will ask you to breathe in a harmless, tasteless mixture of gases through a mouthpiece, hold your breath for around 10 seconds and breathe out until you are empty.
Lung Volumes
This test helps us to measure the total size and all the subdivisions of your lungs. Most commonly you will be asked to breathe normally through a mouthpiece for 2 to 10 minutes, followed by a full breath in and exhalation until you are fully empty. Your Healthcare professional may request that this Lung Volumes test is performed in a different way, depending on the reason for your referral. This other method involves making breathing efforts through a mouthpiece, whilst seated in a large glass box.