Tobacco contains many substances that can harm the body . The three most dangerous substances are nicotine , tar and carbon monoxide . When tobacco is smoked , the smoker inhales nicotine. which has harmful effects on the body . It can speed up the heartbeat and raise blood pressure . In addition nicotine is an addictive drug . After getting used to an addictive drug , the body will want it all the time . It is very difficult to break nicotine addition , even for smokers who really desire to stop smoking .
About 30 percent of tobacco smoke is made up of tar . Tar is a drug sticky mixture of many chemical . It can damage cells in the respiratory system , consequently germs that cause diseases are able to enter the lungs , as well .
Burning tobacco also gives off carbon monoxide . This is the same poisonous gas emitted by cars . Whether carbon monoxide is inhaled from cigarettes or from cars , it causes less oxygen to be carried by the blood thought the body .
Nicotine tar and carbon monoxide can led to diseases of the respiratory system and circulatory system . These substances can affect people who do not smoke as well as those who do . People who do not are more likely to get these diseases if they breathe in tobacco smoke from the air . Today many public places are divided into smoking and no smoking areas . Even on a plane , nowadays , you are not allowed to smoke all the time of the flight however long it is . In this way , people who don't smoke can stay away from harmful tobacco smoke .
People smoke for many reasons . ADS in newspaper and magazines show smokers as healthy people having fun . Young people may start smoke to smoke because they think it makes them look older . They may also smoke because their friends do .
Yet more and more people nowadays heed the warning . They want to stay healthy . One of the ways to stay healthy is to abstain from smoking .