Smoking is an addiction that kills thousands of people every year. It is not known exactly why one person gets addicted to smoking and another doest not, or why certain people are more likely to develop sever illness from smoking. But certain elements increase a person's risk of starting and getting addicted with the habit, and then falling ill from it. Peer pressure often causes teens to start smoking to appear cool. Over all image of smoking from media and billboards portray smoking as sexy and fun; they neglect the realty that smoking can make them sick and corrupt their looks. People often smoke to calm down, ease depression, or enhance pleasure because of their social habits. They find it comforting to perform the practice of lighting a cigarette and even holding or gesturing with one. Living with a smoker also increases the risk of starting and staying with cigarette smoking. .
A major effect of smoking is the limitation of air in and out of the lungs. The lung disease emphysema caused by smocking damages and destroys tiny air sacs of the lung which limits the lungs ability to bring in oxygen and remove carbon dioxide. Tar and other molecules sink in to the lungs causing lung cancer and destroy tiny cells that clean, protect, and get rid of alien particles from lungs. This effects the body in shortness of breath, reduced fitness, lasting coughs and more colds and flu. Most of the smoke taken into the lung is distributed into the body and only ten percent of the smoke is exhaled. Cigarette smoke disrupts normal operation of lungs by increasing the production of mucus, making it hard to clear this mucus out of lungs, destroying some of lung tissue. .
Smoking significantly increases the risk of heart disease for smokers. Nicotine elevates heart rate, increases blood pressure, and compresses blood vessels. Carbon monoxide (the deadly gas produced from cigarette smoke) decreases the transfer of oxygen to the heart, resulting in an increase risk of heart attacks and strokes.