Nicotine is defined by St. John Medical Center as an active and potentially poisonous ingredient in tobacco that directly stimulates the nervous system. According to the National Institute on Drug Abuse, nicotine is one of the most heavily used addictive drugs and the leading preventable cause of disease, disability and death in the U.S.
Addiction
Nicotine may be absorbed through the lungs, mucous membranes in the mouth or nose and even the skin. Once absorbed, nicotine quickly moves into the blood stream and travels to the brain within seconds. In the brain, nicotine mimics the neurotransmitter acetylcholine. Acetylcholine participates in a variety of body functions including breathing, heart rate, learning, muscle movement and releasing other neurotransmitters and hormones affecting appetite and mood. Nicotine activates feelings of reward and pleasure, which causes a desire to repeat usage thereby leading to addiction. Quitting the use of tobacco is usually accompanied by unpleasant nicotine withdrawal symptoms, including hunger, depression, restlessness, headaches, irritability and anxiety.
Heart Disease
According to the American Heart Association, nicotine may increase the risk of heart disease due to artery damage and increased blood pressure. Nicotine causes the heart to beat faster and the blood vessels to narrow which raises blood pressure. Additionally, inhaled carbon monoxide from cigarettes may damage the walls of the arteries thereby promoting fatty buildup, also known as atherosclerosis.
In a study conducted by Weill Cornell Medical College in 2007, results indicated mice exposed to cigarette smoke with high levels of nicotine had significantly larger atherosclerotic lesions compared to mice exposed to lower amounts of nicotine. Additionally, researchers found that as nicotine levels increase, the production of nitric oxide, a chemical made by the body to protect the lining of the blood vessels, decreases.
Overdose/Poisoning
Nicotine poisoning is simply defined as too much nicotine. Acute nicotine poisoning generally occurs when children accidentally chew on nicotine gum, patches or tobacco products. Symptoms include abdominal cramps, agitation, twitching, rapid or the cessation of breathing, coma, confusion, convulsions, breathing difficulties, drooling, fainting, headache, vomiting and weakness. If nicotine poisoning is suspected, call 911 or poison control immediately.
Associated Effects
Nicotine is not generally consumed on its own. It is predominantly found in tobacco products, which may be smoked, chewed, sniffed or dissolved. When ingested in these forms, nicotine is not the only health hazard. According to the American Lung Association, "Cigarette smoke contains over 4,800 chemicals, 69 of which are known to cause cancer." Smoking is responsible for approximately 90 percent of deaths from lung cancer and chronic obstructive pulmonary disease (COPD). Diseases and disorders caused by smoking include COPD, stroke, coronary heart disease, abdominal aortic aneurysm, acute myeloid leukemia, pneumonia, cataract, periodontitis, infertility, peptic ulcer disease and cancers of the bladder, esophagus, lung, larynx, mouth, throat, cervix, kidney, stomach and pancreas.
MayoClinic.com reports that smokeless tobacco such as snuff, plug, chewing tobacco, twist, snus and dissolvable tobacco products contain approximately 30 cancer-causing substances. Health problems related to this type of tobacco use include tooth decay, gum disease, and cancer of the mouth, cheek, gums, lips, tongue throat, pancreas and kidneys.
