Tobacco is a tall, leafy annual plant, originally grown in South and Central America, but now cultivated throughout the
world, including southern Ontario. There are many species of tobacco; Nicotiana tabacum (or common tobacco) is used to produce
Nicotine, a powerful central nervous system stimulant found naturally in the tobacco leaf, is classified as a drug. Nicotine
is one of the main ingredients in tobacco. In higher doses, nicotine is extremely poisonous. It is commonly used as an insecticide.
Tobacco leaves can be burned and inhaled (in the form of cigarettes, cigars, pipes, smoke, etc.) or absorbed through the
mouth (in the form of spit tobacco, chew, or snuff). The membranes in the nose, mouth and lungs act as nicotine delivery systems
- transmitting nicotine into the blood and to the brain.
Smokers usually feel dizzy and sick when they first inhale the nicotine in tobacco, but gradually build up tolerance to
its effects. Other symptoms new smokers experience includes coughing, a dry, irritated throat as well as nausea, weakness,
abdominal cramps, headache, coughing or gagging. These symptoms subside as the user develops a tolerance to nicotine.
Nicotine is highly addictive. The addictive effect of nicotine is the main reason why tobacco is widely used. Many smokers
continue to smoke in order to avoid the pain of withdrawal symptoms. Smokers also adjust their behaviour (inhaling more deeply,
for example) to keep a certain level of nicotine in the body.
Smokers who usually smoke at least 15 cigarettes per day and/or smoke their first cigarette of the day within 30 minutes
of waking are likely to experience nicotine withdrawal symptoms. They will likely find quitting uncomfortable.
Stopping can produce unpleasant withdrawal symptoms including depression, insomnia, irritability, difficulty concentrating,
restlessness, anxiety, decreased heart rate, increased appetite, weight gain, and craving for nicotine.
Symptoms peak from 24 to 48 hours after stopping and can last from three days up to four weeks, although the craving for
a cigarette can last for months.
Most smokers make an average of three or four quit attempts before becoming long-term non-smokers. Relapse is the rule
rather than the exception and must be viewed as part of the process of quitting.