Reversibility of airway obstruction vs bronchodilatation: do we speak the same language?

Airway reversibility test (or bronchodilatation test) is performed routinely in the diagnosis of obstructive lung diseases. The results of this test may be helpful in the diagnosis and differential diagnosis of asthma and chronic obstructive pulmonary disease (COPD), but sometimes bring confusion. Unfortunately, the nomenclature used for test result is not uniform, which also leads to confusion. Next the reader will find an attempt to order the state of affairs and the introduction of a uniform nomenclature, which would be consistent with the logic and allow for unambiguous classification of reversibility test results to facilitate future decisions based on the differential diagnosis.