Chronic obstructive pulmonary disease (COPD) is a group of long-term, irreversible diseases that make it difficult to breathe because air does not flow easily out of the lungs. Over time, COPD gets worse and may lead to severe shortness of breath, heart problems, and death.

The two diseases that typically are associated with COPD are chronic bronchitis and emphysema. These are both caused by smoking tobacco.

• In chronic bronchitis, inflammation occurs in the tubes that carry air to the lungs (bronchial tubes), narrowing the bronchial tubes and making it hard to breathe. The main symptom of chronic bronchitis is a cough that brings up mucus (sputum).
• In emphysema, lung tissue and the tiny air sacs (alveoli) at the end of the bronchial tubes are damaged, trapping air in the lungs. This leads to shortness of breath, the main symptom of emphysema.

Other lung irritants that are inhaled over a long period of time—such as secondhand smoke, air pollution, industrial dust, and chemical fumes—are believed to contribute to COPD.

COPD cannot be cured, but it can be managed. The only reliable way to slow the disease is to stop smoking. Medicines may reduce or relieve symptoms. Lifestyle changes, such as exercising, doing breathing exercises, and taking rest breaks, may help reduce symptoms.

A COPD exacerbation is a sudden increase in shortness of breath and wheezing and possibly an increased cough with or without mucus. A COPD exacerbation can be life-threatening, and hospitalization may be needed.