Chronic obstructive pulmonary disease (COPD)
The term COPD has replaced the previously separate conditions of chronic bronchitis and emphysema.
Bronchitis affects the lining of your bronchi - the main airways that lead from your windpipe (trachea) to your lungs. The lining becomes irritated and inflamed if you have chronic bronchitis and produces excess mucus that blocks the airways.
Emphysema affects your alveoli - the tiny air sacs where oxygen passes into the blood. Emphysema damages the structure of the alveoli causing the walls to break down.
The effects of COPD mean less oxygen passes into your blood.