What is spirometry?

The patient is invited to blow as fast and as hard as possible through a mouthpiece connected to a measuring device, called the spirometer. During this forced exhalation, the device measures several parameters that are then compared to those that would be obtained from another person of the same age, gender, and size, known as ‘normal’, given that they had no respiratory problems..

What is the purpose of spirometry?

Spirometry can be performed for a diagnostic purpose (it can even be abnormal in some respiratory diseases). It can also help assess the impact of a disease on respiratory function. It is also used to follow the disease evolution or effectiveness of a treatment.


The examination takes between 15 and 45 minutes.

How to prepare for it?

Bronchodilator drugs must be stopped before performing the test with a variable delay.

Short-acting medications (Atrovent®, Ventolin®, Berotec®, Duovent, etc.) should be stopped 6 hours before the test, and long-acting medications (Serevent®, Oxis®, Foradil®, Seretide®, Symbicort®) at least 12 hours before the test. It is recommended to stop smoking 6 hours before the test.

Similarly, it is advisable to avoid physical exercise or exposure to cold and fog in the two hours preceding the test.


Spirometry requires the active collaboration of the patient. After the first measurement, a second test can be performed 15 minutes later so as to assess the effect of the administered medication.

Risks and inconveniences

Coughing may occur during forced exhalation manoeuvres.


Patients with a contagious disease are asked to report it to the staff so that appropriate measures can be taken. Pulmonary tuberculosis is a contraindication to spirometry.


Pneumology consultation secretariat

+32 2 764 19 02
Floor: -1 Road: 361