I've heard quite a lot of different answers for this one. Some people say yes they do but it takes upwards of 10-20 years, and some people say no, they never completely heal and you're screwed for life.
I'm 19 and I had my first cigarette about a year and a half ago. I usually have 2-3 a week, sometimes less, but never more than 4 a week.
I notice that my chest becomes tight after running and that I run out of breath a little more easily but nothing aside from that. I'm not concerned with lung cancer as everyone in my family is a heavy smoker and no one has had lung cancer yet (i'm talking about a pack a day or more for 30 years for my grandparents who have never had lung problems period).
Any help would be appreciated.