The primary aim of our study is to examine the relationship between balance and respiratory function, respiratory and peripheral muscle strength, functional capacity, and cognitive function in patients with Chronic Obstructive Pulmonary Disease (COPD). The secondary aim of our study is to compare respiratory function, respiratory and peripheral muscle strength, functional capacity, balance, and cognitive functions of COPD patients and healthy individuals. This study will examine and record the participant's sociodemographic information and medical records. Balance, respiratory function, respiratory and peripheral muscle strength, functional capacity, and cognitive function will be assessed. Since the patients are included in this study, no intervention will be made, no additional tests will be performed, or no changes will be made in the routine treatments of the patients during the study.

COPD Group Inclusion Criteria:

• Being diagnosed with COPD in accordance with the GOLD criteria
• Being between the ages of 40-65
• To be able to speak, read, understand, and cooperate in Turkish
• Being a volunteer to participate in the study

COPD Group Exclusion Criteria:

• Having a COPD exacerbation in the last 8 weeks and/or having an unstable clinical condition
• Having a diagnosed vision, hearing, or neurological disease that may affect balance
• Having any other neurological, orthopedic, cardiovascular, thoracic, or metabolic disease or pathological condition that would affect assessments
• Resting saturation below 90% during exercise tests
• Being on long-term oxygen therapy

Control Group Inclusion Criteria:

• Being between the ages of 40-65
• To be able to speak, read, understand, and cooperate in Turkish
• Being a volunteer to participate in the study

Control Group Exclusion Criteria:

• Having a diagnosed vision, hearing, or neurological disease that may affect balance
• Having any other neurological, orthopedic, cardiovascular, thoracic, or metabolic disease or pathological condition that would affect assessments
• Resting saturation below 90% during exercise tests

Patients with COPD aged between 40-65 years and healthy adults aged between 40-65 years will be included in the study. Informed consent forms for the study prepared for both the COPD group and the control group will be carefully explained and the participants will be included in the study after they have read, understood, and accepted.