COPD Overview

What is COPD (chronic obstructive pulmonary disease)?

COPD is an umbrella term for a range of progressive lung diseases. Chronic bronchitis and emphysema both can 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 increasingly difficult 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 in and out of the lungs.

Small, hair-like structures on the inside of the bronchial tubes (called cilia) normally move mucus out of the 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 the lung. The 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.

How common is COPD?

COPD affects nearly 16 million Americans, or about 6% of the U.S. population.

Who gets COPD?

The primary cause of COPD is smoking. But not all smokers develop the disease. You may be at higher risk if you:

  • Are a woman.
  • Are over the age of 65.
  • Have been exposed to air pollution.
  • Have worked with chemicals, dust or fumes.
  • Have alpha-1 antitrypsin deficiency (AAT), a genetic risk factor to develop COPD.
  • Had many respiratory infections during childhood.

What causes COPD?

Smoking tobacco causes up to 90% of COPD cases. Other causes include:

  • Alpha-1 antitrypsin (AAT) deficiency, a genetic disorder.
  • Secondhand smoke.
  • Air pollution.
  • Workplace dust and fumes.

Smoking

Tobacco smoke irritates airways, triggering inflammation (irritation and swelling) that narrows the airways. Smoke also damages cilia so they can’t do their job of removing mucus and trapped particles from the airways.

AAT deficiency

AAT (alpha-1 antitrypsin deficiency) is an uncommon, inherited disorder that can lead to emphysema. Alpha-1 antitrypsin is an enzyme that helps protect lungs from the damaging effects of inflammation. When you have AAT, you don’t produce enough of the enzyme, called alpha-1 antitrypsin. Your lungs are more likely to become damaged from exposure to irritating substances like smoke and dust.

What are signs of chronic obstructive pulmonary disease (COPD)?

  • Cough with mucus that persists for long periods of time.
  • Difficulty taking a deep breath.
  • Shortness of breath with mild exercise (like walking or using the stairs).
  • Shortness of breath performing regular daily activities.
  • Wheezing.

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