What is COPD?
There are 2 main diseases that cause this obstruction. Most patients have both.
- Chronic bronchitis produces excess mucus that blocks your bronchial tubes. The lining of the airways may become irritated or inflamed, and the airway muscles may spasm. A cough with mucus that lasts 3 months for 2 years in a row may be chronic bronchitis.
- Emphysema affects the air sacs in your lungs. The air sacs, called alveoli become enlarged. As air sacs get bigger, the walls between the sacs are stretched thin and cannot spring back to their normal size. Many air sac walls are destroyed. The larger air sacs do not work well and trap stale air inside. It then becomes difficult for fresh air with oxygen to enter the sacs and blood stream.
The smallest airways, which are called the bronchioles, also weaken. They become less able to stretch. When you breathe out (exhale), these very small airways may collapse before they empty out. Then even more air is trapped in the air sacs.
