In addition to case history and clinical examination, the basic diagnostic work-up of chronic obstructive pulmonary disease comprises in particular lung function testing by means of spirometry. In the event of an uncertain diagnosis, or in a search for underlying causes, an additional EKG, chest X-ray and bronchospasmolytic testing to determine the reversibility of the airways obstruction are employed. In COPD patients younger than 50, as well as in those with pulmonary edema largely confined to the basal fields, determination of the alpha-1-antitrypsin should be carried out. In the case of an exacerbation of the clinical presentation, the sputum should be cultured to determine the possible presence of pathogenic bacteria. Recurrent exacerbations or a rapid worsening of dyspnea necessitate hospitalization