Lung function measurement (also called spirometry) involves measuring the amount of air in the lungs as well as the air speed when breathing. Lung diseases such as asthma or COPD can be detected or their therapy can be controlled. It is usually done to clarify the cause of chronic cough or shortness of breath (dyspnoea), suspected diseases of the respiratory tract, lungs or heart, suspected diseases of the respiratory muscles, tobacco consumption, as a lung function test before operations or for general preventive health care. The measurement of lung function also plays a role in occupational health checks for the prevention and diagnosis of occupational diseases.

To measure lung function in the practice, the patient receives a mouthpiece that leads to a measuring device. This mouthpiece must be firmly enclosed with the lips. The nose is closed with a nose clip. On instruction, the patient now breathes in and out through the mouthpiece for about five to ten minutes according to certain commands. By means of a recording, the doctor can now see how strong the respiratory flow is and what the parameters for the lung function are. For meaningful findings, it is very important that the patient follows the instructions exactly during the examination and cooperates well!