Chronic obstructive pulmonary disease, or COPD, is a progressive lung disease that, over time, makes it more and more difficult to breathe. The term COPD includes two main conditions, emphysema and chronic bronchitis. Emphysema involves damage to the air sacs in the lungs while bronchitis is marked by inflammation of the bronchial tubes, the airways to the lungs. Most people diagnosed with COPD have both emphysema and chronic bronchitis.

The usual cause of COPD is long-term exposure to lung irritants, and the most common irritant—causing 80- to 90-percent of cases—is cigarette smoke.

“Early on in COPD, people may not have any symptoms, or just a little cough in the morning that they attribute to their smoking,” says Dr. Alan H. Gross, of Premier’s Internal Medicine Division. “It’s not until the disease is well advanced that people start noticing they’re short of breath when performing regular activities. Even then, many people ignore the symptoms and instinctively just start to limit their activities—not walk as fast, not exercise as vigorously—and think ‘oh, it’s just that I’m getting older.’ They don’t realize they’re having progressive limitations to their breathing.”

Typically, COPD doesn’t develop in people until after the age of 50, but there are many exceptions to the norm. “For reasons we don’t totally understand,” says Gross, “some people are more susceptible to the harmful effect of smoking than others; women tend to be more susceptible to COPD than men who engage in the same amount of smoking; an uncommon genetic condition— Alpha-1 antitrypsin deficiency—can lead to rapid development of COPD in people before age 40.

“The easiest way to diagnose the disease early,” says Gross, “is with spyrometry, a simple breathing test done in a physician’s office. It’s just a matter of blowing into a computerized machine that measures how much air you’re blowing out and how fast it’s blowing out. The test gives a very good indication of early disease and a good picture of how much the disease has progressed.”

There are many medications that can be helpful in improving the quality of life of people with COPD, alleviating shortness of breath and improving symptoms such as chronic cough. But the best thing a smoker with COPD can do is to quit. “It’s never too late to stop smoking,” says Gross. “In the advanced stages of COPD, very little can be done to reverse the disease, and people will require oxygen.”

Dr. Gross advises anyone who has smoked for more than 10-years to ask for a spyrometry test. At the very least, knowing how much their breathing has been compromised may help them gather the will to quit.