Please explain why tobacco causes lung cancer?

It's complicated. Smoking accounts for the vast majority (but not all) cases of lung cancer. Cigarette smoke contains many substances (carcinogens) that predispose to cancer. They do this in different ways, like interfering with normal lung cell functions, making them divide more rapidly or die more slowly, or by suppressing the normal immune response to tumors. Don't smoke.

Related Questions

What exactly is it that causes lung cancer. Is it the nicotine, the tobacco, or the smoke?

The smoke. It is the smoke that causes the lung cancer. The smoke causes an intense inflammatory reaction in the lungs, and when this continues for years and years, it can cause lung cancer. Now, the nicotine itself doesn't usually cause the cancer, but it is more addictive than heroin. Thus, you get hooked on the cigarettes, which have the smoke, which causes the cancer. A very, very sinister product.
Carcinogens. The burning and smoke contains bad irritants- carcinogens.

As a doctor do you feel that tobacco is the main cause of lung cancer, or is it the chemicals big companies pt, or is there not enough research?

Tobacco is toxic. The tobacco is the main cause of the cancers. It is carcinogenic.
Lung Cancer. There is no question that lung cancer is more common in smokers. Smoking is considered the #1 risk factor. However, as many as 1 out of 3 lung cancer victims are non-smokers. Exposure to asbestos, radium or other toxic chemicals can contribute to lung cancer. Lung cancer is the most common cause of cancer deaths among men and women in the US. Thanks for trusting HealthTap!
YES, But not because of the nicotine that gets you hooked, but from all the other components such as the tar and the heat of the smoke is also a factor. Do non- smokers get lung cancer, yes they do but not in the high numbers we see from first hand and second hand smoke from tobacco. The only chemical that has been a cause for concern is the addition of extra nitcotine in the tobacco, but can't prove.
Not sure. No one can really attribute how much harm comes from the tobacco leaf vs the paper vs the chemicals added but all three are burned and inhaled and lead to disease.

Can you get lung cancer from smoking tobacco / nicotine free herbal cigarettes?

Yes. You can get lung cancer from smoking anything. Tobacco, marijuana, herbs, etc. Inhaling the ash and smoke contains potent carcinogens that increase your risk. Stop smoking to improve your health!
Yes. While the majority of research is on inhaled tobacco and to a far lesser degree marijuana, what we have learned is that in general, inhaling any products of combustion may be associated with pathologic changes and development of malignancy.
Yes. Smoke is an irritant to the lining of the lungs, causing the body to react and "defend" against the irritation and try to remove the smoke particles. Some smoke compounds are known to cause cells to become cancerous.

Has anyone ever got lung cancer from smoking marijuana And never smoking tobacco? I cant find any documented cases no matter how hard I look

Marijuana contains. Carcinogens, some in comparably higher levels than in cigarettes, so there is a theoretical risk. However, clinical studies have failed to demonstrate a clear association with lung cancer.