[Dyspnea. From the concept up to diagnostics].

Dyspnea represents one of the most frequent and heterogeneous symptoms. The term dyspnea describes the subjective perception of an inadequate effort to breathe. In general, acute and chronic forms have to be differentiated. Due to its prognostic implications a structured work-up to find the correct diagnosis is of great importance. Depending on the condition of the patient, simple algorithms including biomarkers, an electrocardiogram, echocardiography and other imaging procedures are used when needed. Especially in its acute appearance life-threatening situations, such as myocardial ischemia, heart failure, pulmonary embolism and pneumothorax have to be rapidly and effectively excluded in the differential diagnostics. In contrast, the underlying diseases in chronic dyspnea are bronchial asthma, chronic obstructive airway diseases, heart failure and a combination of obesity and deconditioning in up to 85 % of all cases. The differential diagnosis needs a structured approach including anamnestic and medical technical methods, aiming an efficient differentiation of cardiac and pulmonary causes. As a high number of patients suffer from more than one significant disease, the differential diagnostic assessment needs to be focused on the assessment of the predominant cause of the dyspnea. For this purpose, exercise tests provide helpful algorithms to answer this question.