Cardiovascular Side Effects

One of the most common cardiovascular side effects from the use of nicotine is an increased heart rate and blood pressure. Nicotine users also have an increased risk of developing coronary artery disease and heart disease, both of which can cause a heart attack that could prove to be fatal.

Respiratory Side Effects

Nicotine can cause respiratory side effects, especially for people who have asthma. Nicotine can also lead to an increased risk of breathing problems due to constriction in blood vessels that carry oxygen, and eventually can lead to lung cancer in users.

Dermatologic Side Effects

For users of the nicotine patch, skin irritation on and around the site of where the patch is placed can occur. This skin irritation may become enough of a problem that the user will have to discontinue the use of the patches. Contact dermatitis, a more advanced skin rash, may also occur.

Gastrointestinal Side Effects

For users of the nicotine patch or nicotine gum, dry mouth, nausea and diarrhea have been reported. The use of nicotine gum may also increase flatulence and hiccups as well as saliva production. None of these effects are too serious, but if they are persistent, can make the user quite uncomfortable and irritated.

Nervous System Side Effects

Between 3 and 12 percent of nicotine users have experienced dizziness, headaches, sleep disturbances and lightheadedness as a result of their use. While these nervous system side effects in and of themselves aren't too serious, they can all lead to a lack of sleep which is a much more serious problem.

Source:

Side Effects of Nicotine