Chronic obstructive pulmonary disease (COPD) refers to a group of lung diseases that block airflow as you exhale and make it increasingly difficult for you to breathe.
Emphysema and chronic asthmatic bronchitis are the two main conditions that make up COPD. In all cases, damage to your airways eventually interferes with the exchange of oxygen and carbon dioxide in your lungs.
COPD is a leading cause of death and illness worldwide. Most COPD is caused by long-term smoking and can be prevented by not smoking or quitting soon after you start. This damage to your lungs can’t be reversed, so treatment focuses on controlling symptoms and minimizing further damage.