Chemicals in Cigarette:
The chemicals in a cigarette include carbon monoxide, Nicotine, and Tar.
Carbon monoxide is a colorless and odorless gas (does not have a smell). It is formed by incomplete burning of carbon. It is found when the car releases gas from its exhaust and in a cigarette. Its molecules combine with the hemoglobin of the blood more readily than oxygen. Meaning that a smoker has far less oxygen in blood than a non smoker which is why he or she cannot perform vigorous activities. This is the reason the smoker coughs all the time.
Tar is a yellow-brown sticky substance found in the cigarette. Tar has hundreds of toxic substances and has 17 known carcinogens which cause cancer. The tar enters the lungs and interferes with the DNA of the lung cells causing it to divide continuously causing a tumor. If a person is lucky he can get the doctor to operate the tumor and prevent lung cancer. The tumor does not effect you and does not cause any pain until it is too late.
Further the tar destroys the cilia found in the trachea causing the mucus to block the wind pipe. The irritants then cause irritation and more mucus is secreted which is why a smoker has a hard time breathing. This disease is called bronchitis.
The tar also reaches the alveoli and destroys its walls and then merges it again causing a lower surface area. This causes even more difficulty to breathe. The disease is called emphysema. It is incurable.
Nicotine is a highly addictive drug. It enters the blood causing a high blood pressure and high heart rate. Because of this the smoker is rapidly addicted to cigarette.
Many smokers smoke because they fear that they have to face the withdrawal symptoms.