emphysema

I am a 41 year old male.  My doctor told me that I probably have the onset of emphysema after smoking for 25 years.  He said if I stopped smoking now, it wouldn't progress.  I was glad to hear that, of course, but I remember years ago my uncle developed emphysema years after quitting smoking and it got worse and worse and he eventually died from it.  Can someone clarify this?

[National Jewish Health]

After 25 years smoking, especially of 1 or more packs daily, there is no guarantee that emphysema/COPD will not progress.  It may or may not, but if it does, it will progress at a much slower rate than it would have had you opted to continue smoking.

With even just, "the onset of emphysema", you should never smoke again.  Every year of not smoking, will increase your longevity.