Nicotine causes the heart to beat much faster. Blood vessels constrict, blood pressure rises, pulse rate increases, and free fatty acids pour into blood. These effects, combined with the stress caused by carbon monoxide in cigarette smoke, are thought to cause 120,000 excess heart attack deaths a year among U.S. smokers. Nicotine has other contradictory effects. It stimulates nerves in muscles, but this quickly gives way to a kind of paralysis.
Nicotine excites the vomiting reflex both in the brain and in the nerves of the stomach.
At first nicotine increases the flow of saliva in the mouth and in the bronchial tubes, but its effects are reversed with later doses. The first thing to remember is that quitting is not easy and requires some work on your part. Don t expect overnight miracles. Set realistic goals to quit and have realistic expectations for accomplishing those goals. Before you actually quit, practice going long periods without smoking.