The most important ingredient of cigarette is nicotine. This chemical when inhaled through cigarettes, moves from the lungs, into the bloodstream and reaches the smoker’s brain within 7 to 10 seconds. Once in the brain, nicotine activates a number of chemical reactions that create temporary feelings of pleasure for the smoker, but these sensations are short-lived, subsiding within minutes. As the nicotine level drops in the blood, smokers feel edgy and agitated. So, to get over from the discomforts, smokers light up another cigarette and this process goes on. One cigarette is never enough for a smoker.

When a person inhales cigarette smoke, the nicotine in the smoke is rapidly absorbed into the blood and starts affecting the brain within 10 seconds. The result is the release of adrenaline hormone. The adrenaline increases a person’s heart rate, blood pressure and restricts blood flow to the heart muscle. When the blood flow is restricted, the smoker experiences rapid, shallow breathing and the feeling of a racing heartbeat. Adrenaline also instructs the body to dump excess glucose into the bloodstream.

Nicotine also inhibits the release of insulin from the pancreas, a hormone that is responsible for removing excess sugar from a person’s blood. This means the smoker has more sugar in his or her blood than normal. High blood sugar acts as an appetite suppressant, which may be why smokers think their cigarettes reduce hunger.

Research has shown that nicotine increases the level of dopamine in the brain, a neurotransmitter that is responsible for feelings of pleasure. The acute effects of nicotine wear off within minutes, so people must continue dosing themselves frequently throughout the day to maintain the pleasurable effects of nicotine and to prevent withdrawal symptoms.

In addition to nicotine, cigarette smoke is composed of more than 4000 toxic chemicals and tar. The tar in a cigarette exposes smokers to an increased risk of lung cancer, emphysema, and bronchial disorders. The carbon monoxide in cigarette smoke increases the chance of cardiovascular diseases.

Now, it has been medically proven, recognised and more widely accepted that the reason people continue to smoke, despite the severe health risks smoking entails, is because nicotine is a highly addictive drug. It is this addiction that leads people into the mirage of smoking for a stress free life .Therefore it is very important that people realise the harmful effects of smoking and quit smoking for a healthy life.