[Etiological and exacerbation factors for COPD. Respiratory tract infections]

Respiratory tract infections are important events in the pathophysiology of COPD, and are known as one of the risk factors for COPD onset. More importantly, they are the most common risk factor of COPD exacerbations. As microorganisms for the causes of infections, both virus and bacteria are representative. Since exacerbations increase the decline in lung function, deterioration in health status and risk of death in COPD, prevention of exacerbations via appropriate long-term management, including smoking cessation, influenza and pneumococcal vaccinations, and pharmacotherapy, is very important. However, if exacerbations occur, early intervention with antibiotics, bronchodilators, and systemic corticosteroids administration should be considered to minimize poor outcomes.