For heavier smokers, this risk is doubled . As you can see, your risk of cancer goes up with the amount of tobacco you are exposed to. Smoking is the major cause of lung cancer in both sexes. It's also the leading cause of deaths related to cancer. More than four out of five lung cancers are linked to cigarette smoking.
Smoking thickens the lining of the lung.
As a result, agents in smoke that can cause cancer get trapped there. This starts a process where normal cells change into cancerous ones. Smoking also makes the lungs less able to clean themselves. Can't smell and taste things like they used to. The moment smoke touches your lips or nose, it begins to attack living tissues.