What is chronic obstructive pulmonary disease (COPD)?

Chronic obstructive pulmonary disease (COPD) is a lung disease that makes it hard to breathe. It is caused by damage to the lungs over many years, usually from smoking.

COPD is often a mix of two diseases:

• Chronic bronchitis (say "bron-KY-tus"). In chronic bronchitis, the airways that carry air to the lungs (bronchial tubes) get inflamed and make a lot of mucus. This can narrow or block the airways, making it hard to breathe.
• Emphysema (say "em-fuh-ZEE-muh"). In a healthy person, the tiny air sacs in the lungs are like balloons. As you breathe in and out, they get bigger and smaller to move air through your lungs. But with emphysema, these air sacs are damaged and lose their stretch. Less air gets in and out of the lungs, which makes you feel short of breath.

COPD gets worse over time. You can't undo the damage to your lungs. But you can take steps to prevent more damage and feel better.

What causes COPD?

COPD is almost always caused by smoking. Over time, breathing tobacco smoke irritates the airways and destroys the stretchy fibers in the lungs.

Other things that may put you at risk include breathing chemical fumes, dust, or air pollution over a long period of time. Secondhand smoke is also bad.

It usually takes many years for the lung damage to start causing symptoms, so COPD is most common in people who are older than 60.

You may be more likely to get COPD if you had a lot of serious lung infections when you were a child. People who get COPD in their 30s or 40s may have a disorder that runs in families, called alpha1-antitrypsin deficiency. But this is rare.

What are the symptoms?

The main symptoms are:

• A long-lasting (chronic) cough.
• Mucus that comes up when you cough.
• Shortness of breath that gets worse when you exercise.

As COPD gets worse, you may be short of breath even when you do simple things like get dressed or fix a meal. It gets harder to eat or exercise, and breathing takes much more energy. People often lose weight and get weaker.

At times, your symptoms may suddenly flare up and get much worse. This is called a COPD exacerbation (say "egg-ZASS-er-BAY-shun"). An exacerbation can range from mild to life-threatening. The longer you have COPD, the more severe these flare-ups will be.

How is COPD diagnosed?

To find out if you have COPD, a doctor will:

• Do a physical exam and listen to your lungs.
• Ask you questions about your past health and whether you smoke or have been exposed to other things that can irritate your lungs.
• Have you do a simple breathing test called spirometry to find out how well your lungs work.
• Do chest X-rays and other tests to help rule out other problems that could be causing your symptoms.