What is COPD (chronic obstructive pulmonary disease)?

What is COPD (chronic obstructive pulmonary disease)?

COPD is an umbrella term for a range of progressive lung diseases. Chronic bronchitis and emphysema can both result in COPD. A COPD diagnosis means you may have one of these lung-damaging diseases or symptoms of both. COPD can progress gradually, making it harder to breathe over time.

Chronic bronchitis

Chronic bronchitis irritates your bronchial tubes, which carry air to and from your lungs. In response, the tubes swell and mucus (phlegm or “snot”) builds up along the lining. The buildup narrows the tube’s opening, making it hard to get air into and out of your lungs.

Small, hair-like structures on the inside of your bronchial tubes (called cilia) normally move mucus out of your airways. But the irritation from chronic bronchitis and/or smoking damages them. The damaged cilia can’t help clear mucus.

Emphysema

Emphysema is the breakdown of the walls of the tiny air sacs (alveoli) at the end of the bronchial tubes, in the “bottom” of your lung. Your lung is like an upside-down tree. The trunk is the windpipe or “trachea,” the branches are the “bronchi,” and the leaves are the air sacs or “alveoli.”

The air sacs play a crucial role in transferring oxygen into your blood and carbon dioxide out. The damage caused by emphysema destroys the walls of the air sacs, making it hard to get a full breath.