Within moments of inhaling a nicotine cigarette, multiple body systems are affected. A sudden release of adrenaline into the bloodstream causes the heart rate and blood pressure to increase. The respiratory system may become irritated, and the digestive system may react with nausea and diarrhea. Nicotine increases dopamine, the feel-good brain chemical in the brain that is mainly responsible for the addictive effect of nicotine use. Long-term effects may include an increased risk of cardiovascular disease and cancer and decreased fertility in men and women.
Some of the most profound effects of nicotine are on a developing fetus. Blood flow is redirected away from the uterus and placenta, affecting development and survival of the fetus. There is an increased risk of spontaneous abortion, premature delivery, and premature detachment of the placenta.
Mothers who smoke during pregnancy double their chances of delivering a baby with a low birth weight. These babies also have a higher risk of Sudden Infant Death Syndrome (SIDS). Children of mothers who smoked while pregnant are at an increased risk of all cancers, especially acute lymphocytic leukemia and lymphoma.
The long-term effects of nicotine use include increased risk of cancer, especially lung cancer. Other cancers caused by long-term nicotine use include cancers of the mouth, throat, and cervix. Smokers have higher incidences of chronic obstructive pulmonary diseases (COPD) like emphysema and chronic bronchitis.
As smoking causes arteries to constrict, this can increase chances of cardiovascular disease. Nicotine use increases risk of high blood pressure, heart attack, and stroke. Smokers are four times more likely to suffer from macular degeneration, a degenerative eye disease that leads to blindness. Nicotine can decrease sperm counts in men and interfere with ovulation and implantation of fertilized embryos in women.
The effects of nicotine differ through the delivery method. Smoking will have more respiratory side effects than use of chewing tobacco or smoking cessation aids, and especially higher rates of respiratory diseases and lung cancer. Smokeless tobacco products are associated with an increased risk of throat and stomach cancers. As smoking cessation aids offer different delivery methods than either smoking or chewing tobacco, there are additional side effects of nicotine to be considered.
Nicotine gum, inhalers, or patches can cause diarrhea and nausea. The nicotine in these products can cause itching, burning, and sweating. This is especially true in smoking cessation aids that involve absorption through the skin, like the patch, nicotine lozenges, and gum. Using any smoking cessation aid too close to bedtime can cause vivid dreams and insomnia. Fortunately, a variety of types of aids are available to minimize the chances of intolerable side effects.