[Chronic cough: practical aspects].

A cough is defined as chronic, if it exceeds 8 weeks in length. Post-nasal drip (PND), bronchial asthma and gastro-esophageal reflux (GERD) must be systematically investigated, as these account for 90 percent of chronic cough cases. In addition to medical history and examination which should exclude either a postinfectious cough or coughing related to ACE inhibitor medication, a new evaluation model suggests chest X ray and spirometry as the initial step. A chronic cough is rarely due to one cause as in at least 25% of cases 2 etiologies are present. An effective treatment of chronic cough often relies on several medication trials until its disappearance. After a multidisciplinary approach to chronic cough using this investigative model, the diagnosis of idiopathic or psychogenic cough should remain exceptional.