COPD is chronic disease that inflames the lungs and obstructs airflow. Symptoms include cough, breathing difficulty, wheezing and mucus (sputum) production.
"Tobacco damages the airways. It damages the substance of the lungs as well and causes emphysema," John Costello, M.D., says. He's a pulmonologist at Mayo Clinic Healthcare, located in London. "It's the major cause of COPD and should be avoided at all costs anyway."
Besides smoking, environmental factors can contribute to COPD, especially in developing countries. Such factors may include living in enclosed spaces with poor ventilation and open fires, exposure to chemicals and other pollutants.
In developed countries, tobacco smoking is the leading cause of COPD. Dr. Costello says, "Certainly, in anybody who's developed the condition, if you want to stop the progress of the condition, you must stop smoking."
Emphysema and chronic bronchitis are common contributors to COPD.
"Chronic bronchitis and emphysema are not the same things, but they are intimately interlinked," Dr. Costello says. The conditions often occur together. Perhaps not surprisingly, smoking is their leading cause.
"One of the definitions of chronic bronchitis is that you have a cough and sputum for more than three consecutive months for two consecutive years, usually the winter months," he says.
Emphysema causes irreversible damage to the lungs' air sacs (alveoli), which causes difficulty breathing. And while the condition cannot be cured, there are treatments, such as medications, breathing therapies and surgery.
Having COPD puts people at risk of other diseases, such as cancer, heart disease and coronary artery disease, Dr. Costello says. And, indeed, at the end stage of the condition, heart failure is possible because blood oxygen is so low.
Dr. Costello acknowledges how difficult quitting smoking can be. So instead of lecturing patients, he presents them with information.
"Every single cigarette smoked does some damage," he says. "The strongest possible advice here is to quit smoking, to avoid smoking and to avoid smoke in your environment if you can do it."