(no my OC, I am attempting to help spread this that I saw first on https://programming.dev/post/33666663 because I think it helps to know that it is not too late to make changes even for major things like smoking and our health!)
There are several lingering consequences, but a lot of the damage can be reversed. This is important to point out because "eh, the damage is done already" is part of the addictive mental gymnastics that keep people smoking. Quitting is always worth it.