[Updating the concept of asthma. Is asthma a syndrome?].

Several symptoms are common to different processes that affect the respiratory system and their precise assessment is key to a correct diagnosis. Amongst those symptoms, mostly dyspnoea oriented toward the possible diagnosis of asthma. Nevertheless, the concept of asthma has changed in recent times, as inflammation of the bronchial tree is valued as the pathogenic base of the process, although it can not be ignored that the bronchial hyperresponsiveness is still the basis of dyspnoea crisis. In the last years, several variants have been established, being defined as phenotypes and endotypes that can identify diverse asthmatic or pseudo-asthmatic processes, and there for it is questioned if asthma is not the only process, but a syndrome. In any case, it cannot be ignored that dyspnoea episodes can be based on bronchial hyperresponsiveness of genetic origin or due to inflammation because of unfavourable environmental conditions, as well as physical exercise or the ingestión of aspirin, processes in which other mechanisms are involved.