Inclusion Criteria:  Age ≥18 years old Consultation motivated by cough lasting for more than 8 weeks (duration corresponding to the definition of chronic cough) Patient covered by a National Health Insurance  Exclusion Criteria:  Active smoker or recent smoking cessation (within the past 6 months) Intake of medications causing cough (the patient can be included 4 weeks after treatment discontinuation if cough persists) Pregnant or breast-feeding women Upper or lower respiratory tract infection within the past 4 weeks Active lung disease (such as interstitial lung disease, lung cancer, abnormal dilation of the bronchi). History of chronic bronchitis. Current treatment with an angiotensin converting enzyme (ACE) inhibitor History of cancer within the past 5 years or active cancer (excluding cutaneous squamous-cell carcinoma). Person not fluent in French Adult not able to express his/her consent verbally Patient refusal