What is tobacco?
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Tobacco is a plant grown for its leaves, which are dried and fermented before being put in tobacco products. Tobacco contains nicotine, an ingredient that can lead to addiction, which is why so many people who use tobacco find it difficult to quit. There are also many other potentially harmful chemicals found in tobacco or created by burning it.
How do people use tobacco?
People can smoke, chew, or sniff tobacco. Smoked tobacco products include cigarettes, cigars, bidis, and kreteks. Some people also smoke loose tobacco in a pipe or hookah (water pipe). Chewed tobacco products include chewing tobacco, snuff, dip, and snus; snuff can also be sniffed.
How does tobacco affect the brain?
The nicotine in any tobacco product readily absorbs into the blood when a person uses it. Upon entering the blood, nicotine immediately stimulates the adrenal glands to release the hormone epinephrine (adrenaline). Epinephrine stimulates the central nervous system and increases blood pressure, breathing, and heart rate. As with drugs such as cocaine and heroin, nicotine activates the brain’s reward circuits and also increases levels of the chemical messenger dopamine, which reinforces rewarding behaviors. Studies suggest that other chemicals in tobacco smoke, such as acetaldehyde, may enhance nicotine’s effects on the brain.
What are other health effects of tobacco use?
Although nicotine is addictive, most of the severe health effects of tobacco use comes from other chemicals. Tobacco smoking can lead to lung cancer, chronic bronchitis, and emphysema. It increases the risk of heart disease, which can lead to stroke or heart attack. Smoking has also been linked to other cancers, leukemia, cataracts, and pneumonia. All of these risks apply to use of any smoked product, including hookah tobacco. Smokeless tobacco increases the risk of cancer, especially mouth cancers.
Electronic cigarettes, also known as e-cigarettes or e-vaporizers, are battery-operated devices that deliver nicotine with flavorings and other chemicals to the lungs in vapor instead of smoke. E-cigarette companies often advertise them as safer than traditional cigarettes because they don't burn tobacco. But researchers actually know little about the health risks of using these devices. Read more about e-cigarettes in our Electronic Cigarettes (e-Cigarettes) DrugFacts.
Pregnant women who smoke cigarettes run an increased risk of miscarriage, stillborn or premature infants, or infants with low birth weight. Smoking while pregnant may also be associated with learning and behavioral problems in exposed children.
People who stand or sit near others who smoke are exposed to secondhand smoke, either coming from the burning end of the tobacco product or exhaled by the person who is smoking. Secondhand smoke exposure can also lead to lung cancer and heart disease. It can cause health problems in both adults and children, such as coughing, phlegm, reduced lung function, pneumonia, and bronchitis. Children exposed to secondhand smoke are at an increased risk of ear infections, severe asthma, lung infections, and death from sudden infant death syndrome.
How does tobacco use lead to addiction?
For many who use tobacco, long-term brain changes brought on by continued nicotine exposure result in addiction. When a person tries to quit, he or she may have withdrawal symptoms, including:
- problems paying attention
- trouble sleeping
- increased appetite
- powerful cravings for tobacco
How can people get treatment for nicotine addiction?
Both behavioral treatments and medications can help people quit smoking, but the combination of medication with counseling is more effective than either alone.
The U.S. Department of Health and Human Services has established a national toll-free quitline, 1-800-QUIT-NOW, to serve as an access point for anyone seeking information and help in quitting smoking.
Government Regulation of Tobacco Products
On May 5, 2016, the FDA announced that nationwide tobacco regulations now extend to all tobacco products, including:
- e-cigarettes and their liquid solutions
- hookah tobacco
- pipe tobacco
This ruling includes restricting sale of these products to minors. For more information, see the FDA's webpage, The Facts on the FDA's New Tobacco Rule.
Behavioral treatments use a variety of methods to help people quit smoking, ranging from self-help materials to counseling. These treatments teach people to recognize high-risk situations and develop strategies to deal with them. For example, people who hang out with others who smoke are more likely to smoke and less likely to quit.
Nicotine Replacement Therapies
Nicotine replacement therapies (NRTs) were the first medications the U.S. Food and Drug Administration (FDA) approved for use in smoking cessation therapy.
Current FDA-approved NRT products include chewing gum, transdermal patch, nasal sprays, inhalers, and lozenges. NRTs deliver a controlled dose of nicotine to relieve withdrawal symptoms while the person tries to quit.
Bupropion (Zyban®) and varenicline (Chantix®) are two FDA-approved non-nicotine medications that have helped people quit smoking. They target nicotine receptors in the brain, easing withdrawal symptoms and blocking the effects of nicotine if people start smoking again.
Can a person overdose on nicotine?
Nicotine is poisonous and, though uncommon, overdose is possible. An overdose occurs when the person uses too much of a drug and has a toxic reaction that results in serious, harmful symptoms or death. Nicotine poisoning usually occurs in young children who accidentally chew on nicotine gum or patches used to quit smoking or swallow e-cigarette liquid. Symptoms include difficulty breathing, vomiting, fainting, headache, weakness, and increased or decreased heart rate. Anyone concerned that a child or adult might be experiencing a nicotine overdose should seek immediate medical help.
Points to Remember
- Tobacco is a plant grown for its leaves, which are dried and fermented before being put in tobacco products. Tobacco contains nicotine, the ingredient that can lead to addiction.
- People can smoke, chew, or sniff tobacco.
- Nicotine acts in the brain by stimulating the adrenal glands to release the hormone epinephrine (adrenaline) and by increasing levels of the chemical messenger dopamine.
- Tobacco smoking can lead to lung cancer, chronic bronchitis, and emphysema. It increases the risk of heart disease, which can lead to stroke or heart attack. Smoking has also been linked to other cancers, leukemia, cataracts, and pneumonia. Smokeless tobacco increases the risk of cancer, especially mouth cancers.
- Secondhand smoke can lead to lung cancer and heart disease as well as other health effects in adults and children.
- For many who use tobacco, long-term brain changes brought on by continued nicotine exposure result in addiction.
- Both behavioral treatments and medication can help people quit smoking, but the combination of medication with counseling is more effective than either alone.
- Nicotine overdose is possible, though it usually occurs in young children who accidentally chew on nicotine gum or patches or swallow e-cigarette liquid.
- Anyone concerned that a child or adult might be experiencing a nicotine overdose should seek immediate medical help.
What are electronic cigarettes?
Electronic cigarettes, also known as e-cigarettes, e-vaporizers, or electronic nicotine delivery systems, are battery-operated devices that people use to inhale an aerosol, which typically contains nicotine (though not always), flavorings, and other chemicals. They can resemble traditional tobacco cigarettes (cig-a-likes), cigars, or pipes, or even everyday items like pens or USB memory sticks. Other devices, such as those with fillable tanks, may look different. Regardless of their design and appearance, these devices generally operate in a similar manner and are made of similar components. More than 460 different e-cigarette brands are currently on the market.1 Some common nicknames for e-cigarettes are:
- hookah pens
- vape pens
- mods (customizable, more powerful vaporizers)
Photo by CDC
How do e-cigarettes work?
Most e-cigarettes consist of four different components, including:
- a cartridge or reservoir, which holds a liquid solution (e-liquid or e-juice) containing varying amounts of nicotine, flavorings, and other chemicals
- a heating element (atomizer)
- a power source (usually a battery)
- a mouthpiece that the person uses to inhale
In many e-cigarettes, puffing activates the battery-powered heating device, which vaporizes the liquid in the cartridge. The person then inhales the resulting aerosol or vapor (called vaping).
E-cigarettes are popular among teens and are now the most commonly used form of tobacco among youth in the United States. Their easy availability, alluring advertisements, various e-liquid flavors, and the belief that they're safer than cigarettes have helped make them appealing to this age group. Further, a study of high school students found that one in four teens reported using e-cigarettes for dripping, a practice in which people produce and inhale vapors by placing e-liquid drops directly onto heated atomizer coils. Teens reported the following reasons for dripping: to create thicker vapor (63.5 percent), to improve flavors (38.7 percent), and to produce a stronger throat hit—a pleasurable feeling that the vapor creates when it causes the throat to contract (27.7 percent).2 More research is needed on the risks of this practice.
In addition to the unknown health effects, early evidence suggests that e-cigarette use may serve as an introductory product for preteens and teens who then go on to use other tobacco products, including cigarettes, which are known to cause disease and premature death. A study showed that students who had used e-cigarettes by the time they started 9th grade were more likely than others to start smoking cigarettes and other smokable tobacco products within the next year.3 Another study supports these findings, showing that high school students who used e-cigarettes in the last month were about 7 times more likely to report that they smoked cigarettes when asked approximately 6 months later, as compared to students who said they didn't use e-cigarettes. Notably, the reverse was not true—students who said they smoked cigarettes were no more likely to report use of e-cigarettes when asked approximately 6 months later. Like the previous study, these results suggest that teens using e-cigarettes are at a greater risk for smoking cigarettes in the future.4 Another study has shown an association between e-cigarette smoking and progression to smoking actual cigarettes.5 This study suggests that e-cigarettes may actually encourage cigarette smoking in adolescents.
Additionally, a study of adult smokers in Europe found those who used e-cigarettes were less like to have stopped smoking than those that didn’t use e-cigarettes. Those that used e-cigarettes also smoked more cigarettes than those who didn’t.6 In another study of more than 800 people who said they were using e-cigarettes to help them quit traditional cigarette smoking, only nine percent reported having quit when asked a year later.7 However, more research is still needed to understand if experimenting with e-cigarettes leads to regular use of smokable tobacco.
Under U.S. Food and Drug Administration (FDA) regulations designed to protect the health of young Americans, minors can no longer buy e-cigarettes in stores or online (see "Government Regulation of E-cigarettes"). The FDA now regulates the manufacture, import, packaging, labeling, advertising, promotion, sale, and distribution of e-cigarettes. This includes components and parts of e-cigarettes but excludes accessories.8
Government Regulation of E-cigarettes
In 2016, the FDA established a rule for e-cigarettes and their liquid solutions. Because e-cigarettes contain nicotine derived from tobacco, they are now subject to government regulation as tobacco products, including the requirement that both in-store and online purchasers be at least 18 years of age (see "E-cigarette Use in Teens"). For more information about this ruling, visit the FDA's webpage, The Facts on the FDA's New Tobacco Rule.
How do e-cigarettes affect the brain?
The nicotine in e-liquids is readily absorbed from the lungs into the bloodstream when a person uses an e-cigarette. Upon entering the blood, nicotine stimulates the adrenal glands to release the hormone epinephrine (adrenaline). Epinephrine stimulates the central nervous system and increases blood pressure, breathing, and heart rate. As with most addictive substances, nicotine activates the brain’s reward circuits and also increases levels of a chemical messenger in the brain called dopamine, which reinforces rewarding behaviors. Pleasure caused by nicotine’s interaction with the reward circuit motivates some people to use nicotine again and again, despite risks to their health and well-being.
What are the health effects of e-cigarettes? Are they safer than tobacco cigarettes?
Some research suggests that e-cigarettes might be less harmful than cigarettes when people who regularly smoke switch to them as a complete replacement. But nicotine in any form is a highly addictive drug. Research suggests it can even prime the brain’s reward system, putting vapers at risk for addiction to other drugs.9
Also, e-cigarette use exposes the lungs to a variety of chemicals, including those added to e-liquids, and other chemicals produced during the heating/vaporizing process.10 A study of some e-cigarette products found the vapor contains known carcinogens and toxic chemicals, as well as potentially toxic metal nanoparticles from the device itself. The study showed that the e-liquids of certain cig-a-like brands contain high levels of nickel and chromium, which may come from the nichrome heating coils of the vaporizing device. Cig-a-likes may also contain low levels of cadmium, a toxic metal also found in cigarette smoke that can cause breathing problems and disease.11 More research is needed on the health consequences of repeated exposure to these chemicals.
Health Effects for Teens
The teen years are critical for brain development, which continues into young adulthood. Young people who use nicotine products in any form, including e-cigarettes, are uniquely at risk for long-lasting effects. Because nicotine affects the development of the brain's reward system, continued e-cigarette use can not only lead to nicotine addiction, but it also can make other drugs such as cocaine and methamphetamine more pleasurable to a teen's developing brain.12
Nicotine also affects the development of brain circuits that control attention and learning. Other risks include mood disorders and permanent problems with impulse control—failure to fight an urge or impulse that may harm oneself or others.12
Can e-cigarettes help a person quit smoking?
Some people believe e-cigarettes may help lower nicotine cravings in those who are trying to quit smoking. However, e-cigarettes are not an FDA-approved quit aid, and there is no conclusive scientific evidence on the effectiveness of e-cigarettes for long-term smoking cessation. It should be noted that there are seven FDA-approved quit aids that are proven safe and can be effective when used as directed.
E-cigarettes haven't been thoroughly evaluated in scientific studies. For now, not enough data exists on the safety of e-cigarettes, how the health effects compare to traditional cigarettes, and if they are helpful for people trying to quit smoking.
Points to Remember
- Electronic cigarettes are battery-operated devices that people use to inhale an aerosol, which typically contains nicotine (though not always), flavorings, and other chemicals. In many e-cigarettes, puffing activates the battery-powered heating device, which vaporizes the liquid in the cartridge or reservoir. The person then inhales the resulting aerosol or vapor (called vaping).
- E-cigarettes are popular among teens. Under U.S. Food and Drug Administration (FDA) regulations designed to protect the health of young Americans, minors can no longer buy e-cigarettes in stores or online.
- Nicotine stimulates the adrenal glands to release the hormone epinephrine (adrenaline) and increases the levels of a chemical messenger in the brain called dopamine. Pleasure caused by nicotine’s interaction with the brain’s reward system motivates some people to use nicotine again and again, despite possible risks to their health and well-being.
- Research so far suggests that e-cigarettes are less harmful than cigarettes when people who regularly smoke switch to them as a complete replacement. But e-cigarettes can still damage a person's health.
- E-cigarettes can lead to nicotine addiction and increased risk for addiction to other drugs.
- E-cigarette use also exposes the lungs to a variety of chemicals, including those added to e-liquids, and other chemicals produced during the heating/vaporizing process.
- More research is needed to determine if e-cigarettes may be as effective as smoking cessation aids already approved by the FDA.
For more information about e-cigarettes, visit:
- the NIDA TV Spotlight on Electronic Cigarettes
- A NIDA Science Spotlight on the association between e-cigarette use and future tobacco cigarette use
- the FDA's webpage, Vaporizers, E-Cigarettes, and other Electronic Nicotine Delivery Systems (ENDS)
- the website, Know the Risks: E-cigarettes & Young People, based on the U.S. Surgeon General's Report on e-cigarette use among youth and young adults; includes various resources such as a parent tip sheet, healthcare provider conversation card, and FAQs
- Notes from the Field: Use of Electronic Cigarettes and Any Tobacco Product Among Middle and High School Students — United States, 2011–2018 (MMRW) (CDC, November 2018)
This publication is available for your use and may be reproduced in its entirety without permission from NIDA. Citation of the source is appreciated, using the following language:
Source: National Institute on Drug Abuse; National Institutes of Health; U.S. Department of Health and Human Services.
- Zhu S-H, Sun JY, Bonnevie E, et al. Four hundred and sixty brands of e-cigarettes and counting: implications for product regulation. Tob Control. 2014;23 Suppl 3:iii3-iii9. doi:10.1136/tobaccocontrol-2014-051670
- Villanti AC, Johnson AL, Ambrose BK, et al. Flavored Tobacco Product Use in Youth and Adults: Findings From the First Wave of the PATH Study (2013-2014). Am J Prev Med. March 2017. doi:10.1016/j.amepre.2017.01.026
- Leventhal AM, Strong DR, Kirkpatrick MG, et al. Association of Electronic Cigarette Use With Initiation of Combustible Tobacco Product Smoking in Early Adolescence. JAMA. 2015;314(7):700-707. doi:10.1001/jama.2015.8950
- Bold KW, Kong G, Camenga DR, et al. Trajectories of E-Cigarette and Conventional Cigarette Use Among Youth. Pediatrics. December 2017:e20171832. doi:10.1542/peds.2017-1832
- Chaffee BW, Watkins SL, Glantz SA. Electronic Cigarette Use and Progression From Experimentation to Established Smoking. Pediatrics. March 2018:e20173594. doi:10.1542/peds.2017-3594
- Kulik MC, Lisha NE, Glantz SA. E-cigarettes Associated With Depressed Smoking Cessation: A Cross-sectional Study of 28 European Union Countries. Am J Prev Med. 2018;54(4):603-609. doi:10.1016/j.amepre.2017.12.017
- Weaver SR, Huang J, Pechacek TF, Heath JW, Ashley DL, Eriksen MP. Are electronic nicotine delivery systems helping cigarette smokers quit? Evidence from a prospective cohort study of U.S. adult smokers, 2015–2016. PLOS ONE. 2018;13(7):e0198047. doi:10.1371/journal.pone.0198047
- Products C for T. Products, Ingredients & Components - Vaporizers, E-Cigarettes, and other Electronic Nicotine Delivery Systems (ENDS). https://www.fda.gov/TobaccoProducts/Labeling/ProductsIngredientsComponents/ucm456610.htm. Accessed April 17, 2017.
- Levine A, Huang Y, Drisaldi B, et al. Molecular mechanism for a gateway drug: epigenetic changes initiated by nicotine prime gene expression by cocaine. Sci Transl Med. 2011;3(107):107ra109. doi:10.1126/scitranslmed.3003062
- Sleiman M, Logue JM, Montesinos VN, et al. Emissions from Electronic Cigarettes: Key Parameters Affecting the Release of Harmful Chemicals. Environ Sci Technol. 2016;50(17):9644-9651. doi:10.1021/acs.est.6b01741
- Hess CA, Olmedo P, Navas-Acien A, Goessler W, Cohen JE, Rule AM. E-cigarettes as a source of toxic and potentially carcinogenic metals. Environ Res. 2017;152:221-225. doi:10.1016/j.envres.2016.09.026
- U.S. Department of Health, and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease, Prevention and Health Promotion, Office on Smoking and Health. E-Cigarette Use Among Youth And Young Adults: A Report of the Surgeon General — Executive Summary.; 2016. https://e-cigarettes.surgeongeneral.gov/documents/2016_SGR_Exec_Summ_508.pdf. Accessed February 21, 2017.
For more information about tobacco products and nicotine, visit our Tobacco/Nicotine webpage.
For more information about how to quit smoking, visit smokefree.gov.