Chronic obstructive pulmonary disease (COPD) is a progressive disease that makes it hard to breathe. Coughing, wheezing, shortness of breath, chest tightness, and heavy mucus production are among the symptoms of COPD. Most COPD patients smoke cigarettes or used to smoke. In COPD, less air flows out of the lungs because air sacs either lose their elasticity or are destroyed. The lungs can also become clogged with mucus and inflamed, leading to breathing difficulties.
