Physical dependence to a drug occurs when an individual's tissue cells get used to a certain level of intoxication. This means the body physically changes, needing the drug in regular doses to maintain its chemical balance. Psychological dependence to a drug occurs when a person needs regular doses of the drug to maintain mental and emotional stability. In either case, a drug dependent person will experience some form of withdrawal symptoms when drug use is discontinued. Physical effects of smoking include irritation of the lung tissues, constricted blood vessels, pupil dilation and increased blood pressure and heart rate.
Smoking often decreases appetite, an unhealthy method of weight control that many women employ.
Chewing tobacco and snuff use cause gum inflammation, gum disease and teeth erosion. Tobacco use stains the skin and teeth, produces bad breath and decreases the ability of the taste buds to distinguish flavors. Chronic physical conditions related to smoking include bronchitis, emphysema, coronary heart disease and stomach ulcers. Women who smoke during pregnancy expose the fetus to the chemicals in the smoke, increasing the risk of stillbirth and neonatal death. A baby born to a smoking woman has a higher risk of low birth weight than one born to a non-smoker.