COPD

A detailed look at the respiratory system and how it works.

Chronic bronchitis is long-term inflammation of the breathing tubes (bronchi). It is common among smokers. People with chronic bronchitis tend to get lung infections more easily. They also have episodes of acute bronchitis, when symptoms are worse.

Emphysema is a chronic lung condition in which the air sacs (alveoli) may be destroyed, narrowed, collapsed, stretched, or overinflated. Pulmonary emphysema is part of a group of lung diseases called COPD. Here's what you need to know.