Spirometry Testing is a standard lung function testing method that evaluates how well your lungs perform by measuring how much air you can breathe out in one forced breath. The spirometry is done by using a device called a spirometer.

Why it is performed

Conditions that can be picked up and monitored using spirometry include:

  • Asthma (a condition in which the airways narrow and swell and produce extra mucus. This can make breathing difficult).
  • COPD (chronic obstructive pulmonary disease) a group of lung conditions where the airways become narrowed.
  • Chronic bronchitis (inflammation (swelling) and irritation of the bronchial tubes).
  • Emphysema (a lung condition that causes shortness of breath. The air sacs in the lungs (alveoli) are damaged.
  • Pulmonary fibrosis (scarring of the lungs).

How to prepare for a spirometry test

  • You should take your daily medications prior to testing unless told otherwise.
  • Avoid wearing clothing too tight that might restrict your breathing.
  • Avoid alcohol consumption as well as big meals on the day of the test, since this may impact your breathing.
  • Do not smoke for at least six hours prior to testing.
  • If you are taking a short-acting inhaler that is used only as needed, do not use for six to eight hours prior to testing, if possible.

The tests are repeated several times to make sure the results are accurate.


During the test, you will be standing upright, and you will be given a mouthpiece connected to the spirometry machine. The procedure is then as follows:

  1. The person inhales as much air as they can to fill their lungs.
  2. The person will then place their lips tightly around the mouthpiece.
  3. The person will breathe directly into the tube as quickly and forcefully as they can for several seconds.

This maximal effort is very important, and testing will be repeated at least three times to get the best results.

The measurements will be compared with a normal result for someone of the same age, height and sex, which will help show if the lungs work properly or if there is an obstructive (such as asthma and COPD), restrictive (such as pulmonary fibrosis) or a combination of the two.

Risks and side effects

Spirometry is generally considered safe. Common experiences during the tests are feeling dizzy, shaky, or tired.

Spirometry may not be safe for people who have uncontrolled high blood pressure, people who have or recently had unstable angina, a heart attack, an operation to the head, chest, stomach, or eyes. For this reason, a screening will be done before commencing with the spirometry testing.