Chronic obstructive pulmonary disease:COPD. Any disorder that persistently obstructs bronchial airflow.COPDmainly involves two related diseases -- chronic bronchitis and emphysema. Both causechronicobstructionof air flowing through the airways andinand out of thelungs. The obstruction is generally permanent and progresses (becomes worse) over time.
Asthma is also apulmonarydisease有妨碍the flow of air out of the lungs, but the obstruction is usually reversible and between attacks ofasthmathe flow of air through the airways is usually good.
COPDis also called chronic obstructive lung disease (COLD).
