[Acute dyspnea].

The leading symptom "acute dyspnea" and the causal underlying diseases have a high risk potential for an unfavorable course of treatment with a high letality. This overview of possible causes, diagnostic procedures and guideline-based therapy is intended to help implement a targeted and structured emergency medical care in the emergency department. The leading symptom "acute dyspnea" is present in 10% of prehospital and 4-7% of patients in the emergency department. The most common conditions in the emergency department with the leading symptom "acute dyspnea" are heart failure in 25%, COPD in 15%, pneumonia in 13%, respiratory disorders in 8%, and pulmonary embolism in 4%. In 18% of cases, the leading symptom "acute dyspnea" is sepsis. The in-hospital letality is high and amounts to 9%. In critically ill patients in the non-traumatologic resuscitation room, respiratory disorders (B-problems) are present in 26-29%. In addition to cardiovascular disease, noncardiovascular disease may underlie "acute dyspnea" and requires differential diagnostic consideration. A structured approach can contribute to a high degree of certainty in the clarification of the leading symptom "acute dyspnea".