Tobacco is one of the most widely used addictive substances in the world. More people use tobacco than all illegal drugs combined. The reason for tobacco's popularity is that it contains a highly addictive drug called nicotine. When tobacco is smoked, chewed, or inhaled, nicotine is rapidly absorbed into the bloodstream and exerts a variety of effects on the body.

People generally use tobacco because it

• produces feelings of pleasure and relaxation
• relieves fatigue and increases alertness

Other effects on behavior can include:

• decreased appetite
• difficulty sleeping

Effects on the body: Nicotine acts directly in the brain to stimulate feelings of pleasure and relaxation. In addition it causes the adrenal glands to release epinephrine (also called adrenaline), a stimulatory hormone that produces an

• increased heart rate
• increased blood pressure
• increased breathing rate

The short-term effects of nicotine resemble those of other stimulants, such as amphetamines and cocaine, although the effects of nicotine are not as intense.

Common street names: Cigarettes are sometimes referred to as smokes, butts, cigs, or bidis (a thin, often flavored, type of cigarette). Smokeless tobacco may be called chew, dip, spit tobacco, or snuff.

How is tobacco used? Tobacco is most often smoked in cigarettes, cigars, or pipes. People also use "smokeless" forms of tobacco, which include chewing tobacco and a powdered form of tobacco (snuff) that is sniffed.

Risk of addiction: Repeated use of tobacco often leads to nicotine addiction. Once a person becomes addicted, it can be extremely difficult to quit. Fewer than 1 in 10 people who try to quit smoking are successful.

Effects on health: The short-term effects of tobacco are relatively mild. However, prolonged use has severe health consequences that make tobacco the leading cause of preventable disease and death in the United States. Long-term smoking raises blood pressure and causes fatal heart attacks, strokes, emphysema, and a dozen different types of cancer. Chewing tobacco causes a variety of different cancers as well. One of every 6 deaths in the United States is caused by tobacco, making tobacco more lethal than all other addictive drugs combined.

How is tobacco produced? Tobacco is a natural substance produced by drying the leaves of the tobacco plant (Latin name Nicotiana).

How long do the effects of tobacco last? A person who smokes a cigarette usually feels its effects within 10-20 seconds, but the effects don't last very long. Most regular smokers experience the desire to smoke another cigarette within 30 to 60 minutes after smoking.

Drug tests for tobacco: When tobacco is smoked, chewed, or inhaled, the nicotine that enters the body is eventually converted by the liver into a substance called cotinine. Cotinine passes into the urine, where it can be detected for up to 4 days after tobacco use.

How many students use tobacco products? About 20% of high school seniors say they have smoked cigarettes and almost 7% have used smokeless tobacco within the past 30 days.