Tobacco is a highly addictive substance. Research has shown that smoking can cause
In short:tobacco, or rather nicotine, changes the way the brain works, making a person want it more. Because of the way it is taken - smoking - nicotine begins to act very quickly. But its effect wears off just as quickly, leaving smokers craving more.
Once in the brain, nicotine attaches tocertain receptors, increases their activity, which leads to an increase in the amount of the stimulating hormone adrenaline. It also increases dopamine levels, which makes people feel good. As a result, the smoker's brain quickly begins to "view" nicotine as a feel-good substance.
Chronic smoking increases the amountnicotinic receptors in the brain. If someone smokes regularly for months and years, their brain becomes addicted to the substance to the point that, after all, "it needs nicotine to function properly." This is why quitting smoking is so difficult.