How Does Smoking Cause Emphysema?

Video Transcript

"Hello, I am Dr. David Burns. I'm a Professor Emeritus at the University of California San Diego School of Medicine. Emphysema is an injury to the lung which causes these very small grape-like structures in the lung called alveoli and there are some three hundred million of them in a normal lung. They're very tiny; too, too small to see with the naked eye; but there, the advantage is that these small little grape-like structures allow you to bring a large amount of blood in a very thin layer close to air that you brought in from the outside. When it does that, the oxygen and the outside air can be absorbed by the blood and the carbon dioxide produced by the body can be transferred to the air and then exhale. What happens with emphysema is that the walls between those alveoli begin to break down and you begin to get as oppose to three hundred million little tiny sacs, you get a smaller number of larger size and some of them can get to be quite large in size, sometimes as large as a grapefruit. When they get that big, they know longer work as well to bring oxygen to the blood because there isn't as much surface for the blood to flow on relative to the volume of air inside those big, grape-big empty holes. One way to think about that is to think about a nylon stocking; had it's head pieces of the nylon broken. It no longer works well because you see big holes and you see that the capacity of that nylon stocking to hold into the skin of the leg is much less. The same is true of the lung. When you loose those walls of the alveoli, you lose the elasticity of the lung and it makes it more difficult for the lung to exhale and causes an inability to get air in and out of the lung; thereby causing substantial shortness of breath and ultimately, if it's severe enough, can cause you to die from respiratory failure. The good news is that if you stop smoking, the rate in which your lung is being damaged will slow to that of someone whose never smoked in year or two. Once that happens, then, if you're not symptomatic; if you're not short of breath at that time that you stop smoking, it's likely that you may never develop respiratory symptoms. So the best advice that we can give to anyone whose concern about chronic lung disease or concern about an emphysema is that they stop smoking as soon as they possibly can."