COPD (chronic obstructive pulmonary disease) is persistent, irreversible obstruction of the airways occurring as emphysema, chronic bronchitis, or both. COPD symptoms include dyspnea and chronic cough, and COPD diagnosis is established by lung function tests. The disease is frequently associated with smoking, and COPD prognosis is improved for patients who cease smoking. COPD treatment typically includes bronchodilators, corticosteroids, and supplemental oxygen. In end-stage COPD, complications such as heart failure and pulmonary hypertension add to disease burden.