Even a few cigarettes a day will affect the body and this trauma builds up over time especially older people whose bodies have slowed down.
The first time I experienced emphysema I couldn't believe it. Going through the motions of breathing and not getting any oxygen - ugly sounds too. Nothing I could do about it but keep on trying. Yet another story of my older body betraying me.
About a year later I quit the few cigarettes a day I was smoking. I wasn't addicted and it was becoming a drag. The ritual that seemed so glorious became a silly chore - look for the best price for a pack, find a place to smoke, open a pack, take one out, light it up, get rid of the butt, enjoy the smoke in my clothes and mouth, get a cup of coffee.
A heads up. For many who've smoked for years the quitting will be painful, and this is separate from breaking nicotine addiction. The body had to make severe adaptations to the daily intake of smoke and it can be also traumatic when the body stops having to do that and begins to repair itself. I had mouth sores, ear infections, and colds for almost a year. Towards the end I began coughing up custard from my lungs. Also, a few years later while thinking about how I used to smoke it felt as if I'd lost a friend - mourning the habit. Smoking had kept me company since college. Anyway, stopping smoking is better than dying or living with emphysema.