COPD | NHLBI, NIH

COPD, or chronic obstructive pulmonary disease, is a progressive disease that makes it hard to breathe. Progressive means the disease gets worse over time. COPD can cause coughing that produces large amounts of a slimy substance called mucus, wheezing, shortness of breath, chest tightness, and other symptoms.

https://www.nhlbi.nih.gov/health-topics/copd