What will happen to a person who quits smoking after 18 years? -
my friend has quit smoking now, but she is been smoking for last 18 years. does it have any bad aspect quitting?
No nothing bad will happen. The farther she is away from a cigarette the better she will feel.
I suspect she will go into a detox state in which the body is flushing out all the harmful stuff that nicotine has left. She might get moody, as she has been so used to it, and irritated.
She will probably go into withdrawal and have strong cigarette cravings. However, she will benefit her health enormously.