This cross-sectional study aims to compare lung ultrasound findings, functional capacity, and dyspnea among patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), patients with stable COPD, and healthy controls. The study will include approximately 60 participants divided into three groups (acute exacerbation COPD, stable COPD, and healthy controls). Participants will undergo comprehensive assessments including lung ultrasound, pulmonary function tests, the Modified Borg Scale, the Modified Medical Research Council (mMRC) Dyspnea Scale, the 6-Minute Walk Test, the 1-Minute Sit-to-Stand Test, the COPD Assessment Test (CAT), the Charlson Comorbidity Index, and the BODE Index. The primary objective is to determine differences in lung ultrasound abnormalities, particularly B-lines, consolidations, and lung ultrasound scores, and to investigate their relationship with functional capacity and dyspnea severity. The findings are expected to clarify the clinical utility of lung ultrasound as a non-invasive bedside assessment tool for evaluating disease severity and supporting comprehensive management of patients with COPD.