[COPD: from early symptoms to chronic respiratory failure].

COPD is a frequent and progressive disease, which can lead to severe respiratory impairment. Smoking is the main causal factor. Therefore, respiratory symptoms should not be underestimated in smokers. Chronic cough, chronic sputum, persistent dyspnea on exercise (even for sustained efforts) need further investigations. Each smoker has to be considered as potentially having COPD. Lung function measurements are required in these patients.