Chronic Obstructive Pulmonary Disease (COPD) is a progressive lung disease that makes it harder to breathe over time. It includes conditions such as chronic bronchitis and emphysema, which cause airflow obstruction and breathing difficulties. COPD leads to symptoms like chronic cough, shortness of breath, wheezing, and excessive mucus production. Over time, COPD can worsen, significantly affecting daily activities and leading to complications like respiratory infections or heart problems.