If your doctor suspects asthma or you have been diagnosed with asthma you may need a lung function (breathing) test.

Lung function testing works out how well your lungs work getting air in and out, and if your asthma affects your breathing. Spirometry is one type of lung function testing.

Most adults and children over 6 years of age can do the spirometry test correctly.

Spirometry breathing tests

It is hard to know what is happening in your lungs without a Spirometry. Spirometry measures the amount of air you can breathe in and out of your lungs, and how hard and fast you can breathe out. It is done with a machine called a spirometer.

Why perform a Spirometry test? Your doctor will organise a test to

  • confirm whether you have asthma
  • work out how severe your asthma is
  • see if your asthma is getting worse
  • see if your asthma is getting better with treatment.
  • check whether the airways in your lungs are narrower than they should be and if there are any other reasons for your symptoms

Both your doctor and you can use the test results to decide if you have asthma, if you need medications, to work out the best dose and if your current medications are working.

What will I have to do for a spirometry test?

The spirometry test is usually done at your doctor’s clinic, or your doctor may refer you to a hospital or other respiratory laboratory.

Before you do the test, the health professional conducting the spirometry will explain how to do it correctly. They will also encourage you throughout the test to breathe out as hard and fast as you can, this test takes all your breathing effort.

You may also be asked to put a special peg on your nose to keep your nose closed so you are breathing out of your mouth, not your nose.

You will need to repeat the test at least three times to get the best result. Sometimes this may not be possible in one visit, because the test can be quite tiring.

The test is not painful – it just needs you to put in your best effort to breathe out as hard as you can!

Sometimes you may be asked to do the spirometry test again after having some puffs of a ‘reliever’ medicine (usually a blue- or grey-coloured puffer). The test will be done about 10 minutes after you’ve taken the reliever to check if the medicine helps your lungs to work better.

Your doctor should always explain your spirometry tests results to you.