Chronic obstructive pulmonary disease (COPD) is a frequent disease which is too often diagnosed when already severe. Major known risk factors are tobacco smoking, occupational exposure, and severe respiratory infections during childhood. Diagnostic should be evoked on functional non specific symptoms: chronic cough and sputum, progressive dyspnea. Some physical signs, correlated with the degree of airway obstruction, may be more specific but their diagnostic value remains to be assessed. These signs reflect distension of the chest as well as airway obstruction: pursed lips breathing, increased expiration duration, Hoover and Campbell signs, inspiratory contraction of scalen muscles. COPD results over years in chronic respiratory insufficiency and evolution is associated with episodes of bronchial and parenchymal infections as well as pulmonary emboli which are particularly frequent in these patients.