The number one cause of chronic obstructive pulmonary disease (COPD)—a disease that includes both chronic bronchitis and emphysema—is smoking. Smoking causes the lungs to become inflamed or damaged, which can prevent air from flowing in and out normally. COPD occurs after tobacco smoke irritates the airways in your lungs and gradually damages the air sacs that provide oxygen to the blood.

There is no cure for COPD, and the lung damage that results in COPD cannot be reversed. But the lung damage can be prevented. The best way to do this is to stop—or not start—smoking. The earlier you quit smoking the better, in terms of lung function. But it's never too late to quit. Although most people think that smoking's greatest danger is lung cancer, COPD is a close second. COPD is responsible for more than 130,000 deaths in the United States each year. (Lung cancer kills 160,000 people each year.)

To find out more about how quitting smoking now can help save your lungs, check out the following information from our A–Z Health Library.