Why Tobacco is a

If you or anyone close to you smokes cigarettes, you're probably well aware that smoking is a habit, one that takes some effort to break. When you smoke, the chemicals in cigarettes are injected into your lungs, your bloodstream and then your brain. Learning some of the facts about tobacco may encourage you to break the habit.

Nicotine Is Habit-Forming

Nicotine, one of the main chemicals in tobacco, is a habit-forming drug that draws the smoker into both a physical and a psychological partnership with cigarettes. Soon after starting to smoke, the smoker may begin to rely on cigarettes for what seems like stimulation, relaxation or stress relief. Meanwhile, the body becomes chemically addicted to nicotine and the more one smokes, the more difficult it is to quit.

More Chemicals

The average cigarette generally contains about 8.4 milligrams of nicotine and 15 milligrams of tar. Tobacco smoke also contains arsenic, cyanide, carbon monoxide and formaldehyde. These are just a few of the 4,000 chemicals found in cigarette smoke, 43 of which are carcinogenic.

Other Sources of Nicotine

Cigarettes are considered one of the most harmful forms of tobacco use because cigarette smokers usually inhale deeply. But pipes and cigars hold risks of nicotine addiction as well. Chewing tobacco and snuff can also cause cancer, gum disease and erosion of the teeth.

Physical Effects

When inhaled, nicotine stimulates the central nervous system. All of the chemicals in a cigarette move to the brain through the bloodstream, causing a sharp rise in blood pressure and heart rate, constricting of the blood vessels and reducing sensitivity to pain and stress. Chronic smokers often have impaired senses of taste and smell, less physical stamina and poorer motor skills. Smoking is among the major causes of heart disease and lung cancer and is the main cause of chronic bronchitis and emphysema. A smoker's skin ages and wrinkles prematurely and female smokers have a higher incidence of unsuccessful pregnancies, stillbirths and lower-weight babies.

Companion Habits

As you become more physically addicted to tobacco, you'll develop other habits that reinforce the role of cigarettes in your daily routine. You may not even realize this is happening. Being with certain friends may trigger your need for a cigarette. Recognizing these connections—and how to break them—can help you in the future if you decide to quit smoking.