What is Tobacco?

Tobacco comes from the leaves of the tobacco plant (Nicotiana tabacum and Nicotiana rustica), which contain nicotine. Nicotine is a stimulant drug. Stimulant drugs act on the central nervous system to speed up the messages traveling between the brain and the body. The leaf of the tobacco plant is dried, cured and aged before having other ingredients added to manufacture a range of tobacco-based products. For example, cigarettes (including some herbal cigarettes), cigars, pipe tobacco, chewing tobacco, and wet and dry snuff.


What Tobacco Does?

Nicotine is highly addictive and acts as both a stimulant and a sedative to the central nervous system. The ingestion of nicotine results in an almost immediate “kick” because it causes a discharge of epinephrine from the adrenal cortex. This stimulates the central nervous system, and other endocrine glands, which causes a sudden release of glucose. Stimulation is then followed by depression and fatigue, leading the abuser to seek more nicotine.


Immediate Effects?

Soon after smoking, chewing or snuffing tobacco, the following effects may be experienced:

  • initial stimulation, then reduction in brain and nervous system activity
  • enhanced alertness and concentration
  • mild euphoria
  • feelings of relaxation
  • increased blood pressure and heart rate
  • decreased blood flow to body extremities like the fingers and toes
  • dizziness, nausea, watery eyes and acid in the stomach
  • decreased appetite, taste and smell.

Tobacco Dependence?

People who use tobacco tend to develop a tolerance to the effects of the nicotine in the tobacco very quickly. This means they need to smoke more and more in order to get the same effect.

With repeated use of tobacco, the risk of dependence on nicotine is high. Dependence on nicotine can be physiological, psychological or both.

People who are physically dependent on nicotine find their body has become used to functioning with the nicotine present and may experience withdrawal symptoms when they reduce their nicotine intake.

People who are psychologically dependent on nicotine may find they feel an urge to smoke/ Chew/ Snuff when they are in specific surroundings, such as at the pub, or in particular situations such as during their lunch break or socialising with friends.

Research has shown that smoking is often associated with different roles and meanings for smokers, including:

  • social roles—such as enjoyment of the company of friends, the drinking of coffee or alcohol, and promoting social confidence and feelings of independence (particularly for young women)
  • emotional roles—caring for the self, such as helping to deal with stress and anxiety, weight control and providing “companionship”
  • temporal roles—such as connecting the flow of events or time in the smoker’s day, providing a break from work or activities and relieving boredom.

What’s in a Cigarette Smoke?

There are more than 4000 chemicals in tobacco smoke. Many of these chemicals are poisonous and at least 43 of them are carcinogenic (cause cancer). The three major chemicals in tobacco smoke are:

  • Nicotine—the chemical on which smokers become dependent
  • Tar—which is released when a cigarette burns
  • Carbon monoxide (CO)—a colourless, odourless and very toxic gas that is taken up more readily by the lungs than oxygen. Smokers typically have high levels of CO in the blood.

This may be why smoking is sometimes referred to as the most difficult drug to give up !