This research study focuses on chronic airway diseases, such as Chronic Obstructive Pulmonary Disease (COPD) and asthma. These conditions make it difficult for patients to breathe, but breathing difficulty (dyspnea) is often perceived very differently. Some patients may feel severe distress with mild breathing problems, while others might not notice significant breathing issues even when lung function is poor. This difference in perception is termed "dyspnea perception."

The main goal of this study is to understand how dyspnea perception varies among patients with chronic airway diseases. The investigators aim to determine if patients can be grouped into different subtypes based on the perception of breathing difficulties. The study will also investigate how these subtypes relate to other treatable characteristics, such as blood cell counts, allergy test results, and findings from lung function tests and brain scans.

Approximately 800 patients with COPD or asthma and 150 healthy volunteers will participate. Participants will answer questionnaires, undergo lung function tests, provide blood samples, and a subset will undergo a special brain scan (functional MRI). No new treatments will be assigned; instead, these characteristics will be observed and measured over time.

It is hoped that this study will help doctors better understand chronic airway diseases and lead to more personalized management strategies for patients in the future.

Participants: The study aims to enroll approximately 800 patients with physician-diagnosed COPD (according to GOLD 2022 criteria) or asthma (according to GINA 2022 criteria), aged 20-75 years, and 150 age-matched healthy controls.

Interventions/Assessments: No investigational interventions will be assigned. Participants will undergo comprehensive assessments at baseline and follow-up visits, including:

Dyspnea perception measurement (using standardized scales). Spirometry, lung volume, and diffusion capacity tests. Fractional exhaled nitric oxide (FeNO) measurement. Blood tests (including complete blood count, total IgE, allergen screening). Health-related quality of life questionnaires (CAT, mMRC, AQLQ, SGRQ). High-resolution computed tomography (HRCT) of the chest. Functional magnetic resonance imaging (fMRI) of the brain (in a subset of participants).

Data on exacerbations, comorbidities, and current medications will be collected.

Inclusion Criteria:

• Inclusion Criteria for Chronic Airway Disease Patients:

  1. Age 20-75 years.
  2. Meets the diagnostic criteria for COPD according to the 2022 GOLD guidelines OR meets the diagnostic criteria for asthma according to the 2022 GINA guidelines.
  3. Willing and able to provide informed consent.

• Inclusion Criteria for Healthy Controls:

  1. Age ≥20 years.
  2. No history of asthma symptoms or diagnosis of chronic respiratory diseases such as asthma or COPD.
  3. Willing and able to provide informed consent and comply with the study protocol.

Exclusion Criteria:

• (applies to all participants):

  1. Respiratory tract infection, COPD acute exacerbation, or asthma acute exacerbation within the past 3 months.
  2. Presence of other diseases causing significant lung tissue destruction, such as severe bronchiectasis or tuberculosis.
  3. History of thoracic or abdominal surgery within the past 3 months.
  4. Heart rate >120 beats per minute.
  5. Ongoing anti-tuberculosis treatment.
  6. Presence of other severe, uncontrolled systemic diseases.
  7. Pregnant or lactating women.

The study population will consist of two groups: 1) a patient cohort of approximately 800 individuals with chronic airway diseases (Chronic Obstructive Pulmonary Disease or Asthma) recruited from hospital clinics and community screening; and 2) a control cohort of approximately 150 healthy volunteers. All participants will be aged between 20 and 75 years.

A definitive plan for sharing individual participant data (IPD) has not been established for this study. The possibility of data sharing is under consideration and will be contingent upon obtaining approval from the institutional review board and ensuring compliance with local data privacy regulations. Further details will be specified in a future update to the registration record if a sharing plan is formalized.