Chronic obstructive pulmonary disease (COPD) is a progressive lung disorder characterized by persistent airflow limitation that makes breathing difficult. It most commonly includes chronic bronchitis, marked by long-term cough and mucus production, and emphysema, in which the air sacs in the lungs are damaged and lose elasticity. The primary cause is long-term exposure to irritants, especially cigarette smoke, though air pollution, occupational dust, and genetic factors such as alpha-1 antitrypsin deficiency can also contribute. Symptoms typically include chronic cough, shortness of breath, wheezing, chest tightness, and fatigue, which often worsen over time. While COPD cannot be cured, treatment—including smoking cessation, inhaled medications, pulmonary rehabilitation, and oxygen therapy—can help manage symptoms, improve quality of life, and slow disease progression.