What is the cause of COPD?

Most commonly, COPD is caused by long-term exposure to irritants (through chemical fumes and air pollution) that can damage the airways and tiny air sacs in the lungs.

The top risk factor in developing COPD is cigarette smoke. Up to 75 percent of people who have COPD smoke or used to smoke. Even secondhand smoke is considered a risk factor, particularly when exposure is prolonged.