Inclusion Criteria:  Candidates voluntarily participate in and abide by the relevant regulations of the study, can cooperate with corresponding inspections, follow the follow-up plan, and voluntarily sign written informed consent.  Patients with chronic cough  Coughing lasting ≥ 8 weeks, There is no obvious abnormality in the chest X-ray No clear history of upper respiratory tract infection in the past 4 weeks, Newly diagnosed or untreated in the last 4 weeks Non-smokers.  Patients with Asthma  For newly diagnosed and previously diagnosed asthma patients, the diagnosis criteria for asthma: Including various disease severity (mild, moderate, severe), various disease states (chronic duration, acute exacerbation period). Non-smokers. Patients with COPD 1) Including patients in stable phase and acute exacerbation phase.  Exclusion Criteria:  Diagnose patients with ACO; Those who cannot cooperate with the completion of research-related test, follow-ups and other reasons cannot cooperate with the progress of the research; Combined with serious diseases of other systems (such as cardiovascular, metabolic, immune, neurological, etc.). With other diseases of the lung, including bronchiectasis.