“Chronic obstructive pulmonary disease (COPD) is an ongoing lung condition caused by damage to the lungs. The damage results in swelling and irritation, also called inflammation, inside the airways that limit airflow into and out of the lungs. This limited airflow is known as obstruction. Symptoms include trouble breathing, a daily cough that brings up mucus and a tight, whistling sound in the lungs called wheezing.

COPD is most often caused by long-term exposure to irritating smoke, fumes, dust or chemicals. The most common cause is cigarette smoke.

Emphysema and chronic bronchitis are the two most common types of COPD. These two conditions usually occur together and can vary in severity among people with COPD}.”

MAYO CLINIC (https://www.mayoclinic.org/diseases-conditions/copd/symptoms-causes/syc-20353679)