CuDLife - I also know many people who are heavy smokers of both weed and cigarettes. I once worked for a guy who literally ALWAYS had a lit cigarette in his hand or in his mouth. I honestly never saw him without one. He must have smoked close to 2 packs a day, and he started when he was in his teens. He is now 70 something and has no real health problems. Some people can just smoke anything and everything anytime and anywhere for their entire lives and never have any significant health impact caused by smoking. However, I know someone who got lung cancer at 54, and they only smoked for 5 or 6 years in their late 20s and early 30s. Everyone is different, and genetics plays a big role. Chances are if a lot of your family smokes and has smoked back through the generations with little or no health problems, you can too. But that is by no means an exact method of determining how much damage smoking will do to you. Ultimately, the act of inhaling any burning substance whether it be weed, tobacco, wood, grass, etc, can only be detrimental to your health. And despite the fact that your lungs do recover somewhat, they will never be as good as before you ever smoked, no matter how long it has been since you quit. In addition, your lungs can be permanently damaged when the tissue in your airways scars, and it is even possible to literally burn holes in your lungs which are never repaired. Another form of permanent damage is in the destruction of the cilia, which are responsible for cleaning the lungs and repairing damaged tissue, is irreversible. Once one is destroyed, it never grows back. Go look up any facts on smoking from a LEGITIMATE source (cross referencing is the easiest way to check legitimacy), and you will find everything i have said to be true, and then some.