The aim of the research is to explore the diagnostic efficacy of impulse oscillation (IOS) before and after bronchial provocation test (BPT) and bronchial dilation test (BDT) in chronic airway disease.

The present study has the following objectives:

to explore the diagnostic value of IOS before and after BPT/BDT in chronic airway disease, to assess the diagnostic accuracy of IOS in chronic airway disease with special regard to its discriminating value between asthma and chronic obstructive pulmonary disease, to evaluate the characteristics of airway resistance after BPT/BDT, to evaluate the airway reversibility and hyperresponsiveness（AHR）in asthma.

Inclusion Criteria:

1. 18-75 years old, no gender limit;

2. The subject voluntarily cooperated with the research and signed an informed consent form;

3. Meet any of the following three criteria:

   • Patients with asthma, the standard diagnosis of asthma complied with the GINA 2019; ② Patients with COPD, the standard diagnosis of COPD complied with GOLD 2019; ③ The subjects in the healthy control group had normal vital capacity (baseline FEV1≥80% of the predicted value, FEV1/FVC was greater than the Lower Limit of Normal, and with negative result of BPT or BDT).

Exclusion Criteria:

1. History of other lung diseases, such as cystic fibrosis, bronchiolitis obliterans, tuberculosis, lung cancer, etc.;
2. After taking corticosteroid therapy in the last 4 weeks, respiratory tract infection occurred within 8 weeks;
3. A history of myocardial infarction and stroke in the past 3 months; a history of severe arrhythmia, severe cardiac insufficiency, and unstable angina in the past 4 weeks, etc.;
4. In the past 4 weeks, severe hemoptysis and epileptic seizures require medication; severe hyperthyroidism;
5. Pregnant women;
6. Other researchers consider it inappropriate.