Lung Function / Spirometry

Spirometry is the most accurate breathing test for asthma. It measures the amount of air you can breathe in and out of your lungs, and how hard and fast you can breathe out. In other words, it measures your overall lung function.
The machine used to do the test is called a spirometer. Doctors use a spirometer to:

• check whether the airways in your lungs are narrower than they should be
• 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.

The test results help you and your doctor to decide whether you need any medicines, or to work out whether the type or dose of your current medicine needs to change. Most adults and children over 7 years of age can do the spirometry test correctly.