What's the side effects of using chewing tobacco, is it dangerous?

Oral cancers: Few people develop oral leukoplakia ( a precursor to oral cancer) or oral cancers (tongue, gums, throat, etc) unless they use tobacco - specifically chewing / smokeless tobaccos. Although cigars and cigarettes also increase those risks as well as the risk for lung cancer.

Yes: Chewing tobacco use causes many problems. It especially increases the risk of cancers of the lips and mouth/throat as well as increased risk of cancers of the digestive tract (esophagus, stomach, etc.) in addition it causes gum disease and tooth loss. If you think dentures are attractive, keep it up!

Yes it is dangerous: Any kind of tobacco places you at increased risk for head and neck cancer including chewing tobacco. The risk of head and neck cancer increases even more if this is combined with long term alcohol abuse.

Cancer: It's just as bad as smoking, except it can give you mouth and throat cancer. Baseball hall-of-famer tony gwynn just had repeat surgery on his jaw for cancer. He spoke about the recovery process, disability, etc. Look it up. Oral cancers are not pretty as the resection is often much larger than the visible tumor.

2 words: oral cancer: Chewing tobacco has been definitively linked with increasing a person's incidence of developing oral or mouth cancer. It can be fatal in some cases and, at a minimum, extremely disfiguring if surgery is required. Most physicians feel the same way: just stay away from tobacco all together and you won't have to worry about any of it's risks! very simple, right?