During the lung function test, the doctor can determine whether the lungs are working properly. Depending on the type of examination, it is measured how much air is moved through the lungs, at what speed and pressure this occurs and in what ratio the respiratory gases oxygen (O2) and carbon dioxide (CO2) are exchanged. In this way, serious lung diseases can be detected at an early stage, sometimes before the patient notices his or her own breathing problems.
Indications
The typical symptoms for which a lung function test is ordered are shortness of breath, coughing and sputum. Of course, the signs of illness must persist over a long period of time in order to give cause for a lung function test. This examination is also useful for smokers, as they have a much higher risk of various lung diseases.
Some patients are also sent to a lung specialist if an x-ray reveals abnormal lung findings or if an unusually high number of red blood cells are found in a blood sample. Since the so-called erythrocytes transport oxygen through the blood, their increased incidence suggests that the lungs cannot otherwise absorb enough vital oxygen. In some cases, however, lung function testing is also carried out as a routine measure. Asthmatics, for example, should undergo the examination regularly. For competitive athletes and some occupational groups, a lung function check is also useful.
Diseases
In classical spirometry, it is checked whether the lungs are sufficiently ventilated, i.e. whether the patient inhales and exhales enough air. If this is not the case, it is called a ventilation disorder. There are different types of ventilation disorders.
Obstructive ventilation disorder: If the airways are narrowed, the patient must always exhale against a certain resistance. The air can no longer easily escape from the lungs. This is the case with bronchial asthma and chronic obstructive pulmonary disease (COPD).
Restrictive ventilation disorder: In some patients, the problem is that the lung or thorax is not flexible enough. This may indicate lung hardening (pulmonary fibrosis), pleural effusion, scarring after lung surgery or diaphragmatic paresis (where the diaphragm is too high).
- Obstructive ventilation disorder: If the airways are narrowed, the patient must always exhale against some resistance.
The air can no longer easily escape from the lungs. This is the case with bronchial asthma and chronic obstructive pulmonary disease (COPD).
- Restrictive ventilation disorder: In some patients the problem is that the lungs or thorax (chest) are not flexible enough. This may indicate lung hardening (pulmonary fibrosis), pleural effusion, scarring after lung surgery or diaphragmatic paresis (where the diaphragm is too high).
- Neuromuscular ventilation disorder: The transmission of signals from the brain to the respiratory muscles is disturbed or interrupted. This is usually due to an injury to the responsible nerves, such as in paraplegia.
