COPD, or Chronic Obstructive Pulmonary Disease, is a lung disease that develops slowly over time and is common among people who have been exposed to tobacco smoke. As the disease progresses, airways narrow and lung tissue becomes damaged, affecting the flow of air through the lungs.
With COPD, people can develop emphysema, chronic bronchitis, or both. Emphysema destroys air sacs in the lungs, which affects outward air flow. Bronchitis inflames the bronchial tubes (also called airways) that link the mouth and nose to the lungs. As the membranes in the bronchial tubes become inflamed due to cigarette smoke exposure and other inhaled irritants, they make more mucus, which clogs the system and restricts air flow even more.
COPD symptoms include cough, shortness of breath, and increased mucus production. The early stages of COPD are easy to overlook, since people may not have specific symptoms until years after the disease begins.