Emphysema or chronic obstructive pulmonary disease (COPD) is the slow destruction of the tissue in the lung. Over time, this makes it harder to get air in and out of the lungs and move oxygen from the lungs into the blood. In the US, COPD is almost exclusively a disease of smokers, and it results from a chronic exposure to the tar and chemicals in cigarette smoke. In less developed countries, COPD often results from cooking in small spaces over open fires. The smoke from cigarettes is actually worse than wood or other smoke due to the nicotine, which paralyzes the small hairs in the airways that are responsible for cleaning out anything that makes its way into the lungs.
Quitting smoking helps COPD in two ways. The first is that you avoid inhaling carbon monoxide, which poisons red blood cells and prevents them from carrying oxygen. This is particularly important for people whose lungs no longer move oxygen into the bloodstream well. The second is that you stop the ongoing damage and worsening of symptoms. Although quitting can’t undo any damage that’s been done, it slows down the progression of the disease, because you aren’t continuing to damage your lungs. It’s never too late to benefit from quitting, even if you have emphysema.
Medical review: Nathan Cobb, MD, April 4, 2018