This study aimed to show the relationship between CAT Score and airway limitation in smokers who applied to MSKU Chest Diseases Polyclinic with respiratory complaints (shortness of breath, cough, sputum, etc.) and underwent respiratory function tests. CAT Score is a measurement used to evaluate the quality of life of Chronic Obstructive Pulmonary Disease (COPD) patients. CAT Score is a scale used to assess patients' symptoms (such as shortness of breath, cough, and sputum) and problems affecting their daily activities. CAT Score usually takes a value between 0 and 40, and a high score may indicate that the patient's quality of life is low. There are studies on the usability of CAT Score in Bronchiectasis, Tuberculosis, and Asthma Diseases other than COPD. We hypothesize that there is a positive correlation between CAT Score and airway limitation in smokers before COPD develops. The study was planned as cross-sectional. Between July 2024 and December 2024, patients who apply to MSKU Chest Diseases Polyclinic with respiratory complaints and have a history of smoking will have their CAT scores, 6-minute walking test, and height and weight measurements performed and recorded. In our study, the comparison of CAT Scores of individuals who smoke and have normal respiratory function test parameters with those who are not normal but excluded from COPD is planned as the primary endpoint, and comparisons of CAT Scores with exercise capacities and body mass indexes are planned as the secondary endpoint.

Inclusion Criteria:

• Smoking history Being over 18 years old Being symptomatic

Exclusion Criteria:

• Having a diagnosis of chronic respiratory disease (COPD, Asthma, IPF)

Patients who applied to MSKU Chest Diseases Polyclinic with respiratory complaints and had a history of smoking were subjected to respiratory function tests.