What are some symptoms after you quit smoking? will you still be able to have lung cancer even after 30 years of not smoking anymore?

Generally yes: Most of the risks from smoking go way down after cessation, but some take years to go down to zero, depending on how long, and how much, you smoked, and how much damage has already been done. Someone who smoked for 20 years will always have some increased risk of lung cancer, but each passing year lowers that risk. It's always worth quitting and staying quit.

Will better: You will thank yourself if you are quitting smoking. You may not do it right away, but you will do it in the future. Your risk for smoking related lung cancer will decrease significantly after 30 years of quitting smoking, although there still be a minimal risk- compared to nonsmoker person. Dont think too much- please quit smoking. Smoking will not do any good to your body.

Yes.: After several years of not smoking, your cardiovascular risk decreases almost to the level of someone who never smoked. Your lung cancer risk decreases, but never back to baseline. The other "symptoms" of not smoking include improved breathing, feeling and sleeping better, and not stinking of tobacco.