Diagnosis of asthma - a new approach.

Current definition of asthma involves four cornerstones: inflammation, hyperresponsiveness, bronchoconstriction, and symptoms. In research, the symptoms have had the slightest attention. According to international guidelines, the asthma symptoms are episodic breathlessness, wheeze, cough, tightness of the chest, and shortness of breath. As there are several symptoms, a primary question is how they are related to bronchoconstriction, the main clinical feature of asthma. Symptoms and lung function tests are regularly used for the evaluation of clinical health status and effect of treatment. However, there is no or poor correlation between these two variables, which means that they represent different mechanisms. Reduced lung function, such as a low FEV(1) , represents bronchial constriction, what do the symptoms represent? Some symptoms such as breathlessness and shortness of breath seem not to be evidence-based asthma symptoms. Focusing on bronchial obstruction is important in view of the potential risk of asthma attacks, but nonobstructive symptoms occur frequently and may also cause severe discomfort and poor quality of life. Interpreting all symptoms as signs of bronchoconstriction (asthma) may lead to misinterpretation when assessing health status and effect of treatment. Although a 'soft' variable, the strength of symptoms is that they are representing various mechanisms. The physiological preconditions for control and defense of respiration must be considered in the diagnostic process, regardless of inflammation, allergy, psychology, or other etiological factors. Based on studies on dyspnea in cardiopulmonary diseases, including asthma and asthma-like disorders, there seems to be a continuous spectrum of symptoms and mechanisms integrated in a single asthma syndrome.