Chronic obstructive pulmonary disease (COPD) is a progressive lung condition characterized by persistent airflow limitation, usually caused by long term exposure to harmful particles or gases, most commonly tobacco smoke. It includes chronic bronchitis, with long standing cough and mucus overproduction, and emphysema, where destruction of alveoli reduces the surface area for gas exchange. Symptoms often begin subtly with exertional breathlessness and intermittent cough, then progress to daily dyspnea, wheeze, frequent respiratory infections and fatigue.

Diagnosis relies on spirometry, particularly a post bronchodilator FEV1 to FVC ratio below 0.7, confirming fixed airflow obstruction. Imaging and symptom questionnaires help classify severity and guide treatment. The disease course is marked by acute exacerbations, usually triggered by infections or pollutants, which accelerate lung function decline, increase mortality risk and worsen quality of life.

Therapy focuses on symptom relief, reducing exacerbations and slowing progression. Inhaled bronchodilators, both short and long acting, are the cornerstone, often combined with inhaled corticosteroids in patients with frequent exacerbations or overlapping asthma features. Pulmonary rehabilitation improves exercise capacity and reduces dyspnea. Smoking cessation is the most effective intervention to alter long term outcomes. Vaccinations against influenza and pneumococcus, oxygen therapy in advanced hypoxemia and in selected cases surgical or bronchoscopic lung volume reduction are additional options.

Preventive strategies emphasize reducing smoking prevalence, occupational exposures and ambient air pollution. Ongoing research explores biomarkers, genetic susceptibility, inflammatory pathways and novel pharmacologic targets to better personalize therapy and identify patients at earlier, more treatable stages.