Nicotine is an addictive ingredient commonly found in cigarettes, and the effects of nicotine on health can be detrimental to anyone ingesting the drug. The immediate effects, however, can seem positive and beneficial. The effects of nicotine on health are generally negative, but nicotine also acts as a stimulant, and smokers have reported feeling heightened awareness, alertness, and calmness while nicotine was in their bodies. The effects of nicotine on health in regard to metabolism can be seen as both positive and negative: nicotine slows the metabolism, encouraging weight loss but discouraging appetite, which can keep valuable nutrients out of the body.
The release of chemicals in the body increase the impact of nicotine on health. Certain chemicals that are stimulated by nicotine only a few seconds after it is introduced into the body can increase memory function and enhance both concentration and alertness. Nicotine also stimulates chemical activity that reduces pain and anxiety. Nicotine is an especially effective drug because it is delivered to the brain rapidly and frequently while a person is smoking and taking many "hits" from the cigarette. Nicotine patches that adhere to the skin also deliver a significant amount of nicotine to the bloodstream very quickly.
While all these effects of nicotine on health seem extremely positive, there are mkany downsides to the drug and its impact on the human body. By itself, nicotine is not especially addictive, but in combination with other chemicals commonly found in cigarettes, nicotine encourages addiction and signals to the body the need for more. If young users are introducing nicotine to their bodies at a young age, it can affect the brain's ability to produce certain chemicals that allow a person to regulate normal body functions. This can encourage addiction to the drug later on in life. Once a person decides to quit smoking, he or she might experience nicotine withdrawal, and while this withdrawal is not as severe as with other drugs, it can still be quite difficult to overcome.
More severe effects of nicotine on health include risk of birth defects in pregnant women, which is why pregnant women are warned not to smoke during pregnancy. Because nicotine raises blood pressure, it can also increase the risk of blood clots, high cholesterol, and dangerously high blood pressure. Because of its addictive nature, and since the most common form of nicotine delivery is smoking, people who smoke regularly and take in nicotine are at greater risk for fatal diseases such as cancer, though nicotine itself is not a direct cause of cancer.