Inhaling cigarette smoke or e‑cigarette vapor exposes the body to nicotine and other chemicals. Cigarette smoke contains roughly 7,000 chemicals – dozens of which are known cancer-causing agents – and it is the leading preventable cause of death in the U.S. E-cigarettes heat a liquid (usually nicotine plus flavorings) into an aerosol. Although e‑cigs have far fewer total toxins than smoke, both products deliver nicotine and harmful substances. Major health agencies agree neither smoking nor vaping is safe. Below we break down what’s in the smoke and vapor, their short- and long-term effects, the scientific consensus, and special advice for teens, pregnant women, and others.
What’s in the smoke and vapor?
Cigarette smoke and e-cigarette vapor both contain nicotine, but their chemical makeup is very different. Tobacco smoke is produced by burning tobacco, creating tar, carbon monoxide and about 7,000 chemicals. By contrast, e-cigarettes create an aerosol from a liquid. This vapor generally contains far fewer chemicals than smoke, but it still delivers nicotine and other toxic substances. For example, e‑cig aerosol can contain carcinogens, volatile organic compounds, flavoring chemicals (like diacetyl) and even heavy metals (nickel, tin, lead) from the device. The CDC notes that while e-cigarettes usually have lower toxin levels, they are not harmless. In short, both smoke and vapor expose the lungs to nicotine and other poisons, but cigarette smoke carries a far heavier chemical load.
Short-term effects on your body
In the short term, both smoking and vaping irritate the lungs and cardiovascular system. People who vape often cough or wheeze after using an e-cigarette. Likewise, smoking immediately provokes coughing, throat irritation and worsened asthma. Nicotine itself (in smoke or vapor) spikes heart rate and blood pressure – a classic “fight or flight” response. For example, vaping has been shown to raise heart rate and blood pressure acutely, just as cigarettes do. Both smoke and vapor also contain fine particles that can trigger inflammation. Inhaling heated vapor produces chemicals like acrolein or formaldehyde, which can irritate lung tissue. (By contrast, modern vaping devices do not produce tar or carbon monoxide, two major smoke toxins.) Overall, whether you inhale smoke or vape aerosol, you may experience cough, shortness of breath or chest tightness in the near term.
Long-term health impacts
The long-term harms of smoking are well-established: smoking causes lung cancer, chronic obstructive pulmonary disease (COPD), heart attacks, strokes and many other diseases. In the U.S. alone, about 480,000 deaths a year are linked to smoking. By contrast, e-cigarettes have only been widely used for about a decade, so their chronic effects are still being studied. Early research shows vaping is not harmless: it can lead to chronic lung and cardiovascular problems. For instance, the American Cancer Society notes that repeated vaping can cause chronic lung inflammation and cell damage, which over time can trigger cancerous changes. Short-term studies have observed that exclusive vapers run a higher risk of lung problems: one large study found people who only vaped had more than double the risk of developing chronic lung disease (COPD) compared to non-users. That same study saw vapers also had higher rates of high blood pressure than non-users. In other words, vaping alone was linked to new cases of lung disease and hypertension, whereas smoking (and especially dual use) showed higher risks across the board.
We still lack decades-long data on vaping, but what we do know is worrying. Vaping aerosol contains some of the same carcinogens found in smoke, so a cancer risk is plausible. A recent study even found that smokers who also vaped had much higher lung cancer rates than smokers alone. Until more is known, experts assume that regular vaping will carry some of the diseases seen with smoking – especially lung disease and heart problems. Importantly, although e-cigarettes avoid many of tobacco smoke’s worst poisons, they still deliver nicotine and other toxins, and long-term use can damage organs. In short: smoking is firmly linked to cancers, lung disease and heart disease; vaping appears less deadly but is still linked to serious illnesses, and the full long-term picture is not yet clear.
What do health experts say?
Public health organizations agree that neither product is safe, but they weigh the risks differently. The CDC notes that e-cigarette vapor generally has fewer toxic chemicals than cigarette smoke. In fact, several agencies (including the USPSTF) state that, aside from nicotine, exposure to toxicants is “significantly lower” with vaping compared to smoking. In practical terms, an adult who completely switches from smoking to vaping will likely reduce their exposure to certain poisons. This is why some experts believe vaping can be less harmful than continued smoking for a longtime smoker.
However, no one calls vaping “safe.” The World Health Organization emphasizes that both cigarettes and e‑cigs “pose risks to health” and that the safest choice is to use neither. The American Heart Association likewise states that e-cigarettes are not a healthy alternative to smoking. They point out that e-cig vapor still contains nicotine, flavor chemicals (like diacetyl), volatile organic compounds and heavy metals (nickel, tin, lead) – all of which can harm the body. In summary, the consensus is: vaping likely carries somewhat lower risk than smoking, but it is far from harmless. Health agencies advise that people who don’t smoke should never start vaping, and those who do smoke should aim to quit entirely using proven treatments (patches, medications, counseling) before turning to e-cigarettes.
Who should avoid smoking or vaping?
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Youth and teens: Developing brains are very sensitive to nicotine. Teen e-cig users quickly become addicted, and research shows vaping makes smoking more likely later on. Health experts strongly advise that kids and young people never use e-cigarettes or smoke. Even short-term nicotine use can harm attention, learning and mood in adolescents.
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Pregnant women: No form of nicotine is safe during pregnancy. Using cigarettes or e-cigarettes while pregnant can damage fetal brain and lung development and raises risks of low birth weight and preterm delivery. Major health bodies recommend pregnant women avoid all tobacco products, including vaping.
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Adults with chronic health issues (heart or lung disease): If you have asthma, COPD, heart disease or similar conditions, both smoking and vaping will worsen your health. Smoking dramatically raises risks of heart attack and stroke; vaping still stresses the lungs and blood vessels. Doctors say the goal for these patients is to stop all nicotine products. In practice, quitting tobacco outright is the best move. If a doctor does consider e-cigarettes (for example, a very heavy smoker unable to quit), it should only be as a last resort, since vaping still poses cardiovascular and respiratory risks.
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Smokers trying to quit: Adults who already smoke are strongly encouraged to use FDA-approved cessation aids (nicotine patches, gum, or medications plus counseling) before trying e-cigarettes. Vaping has not been proven as a reliable quitting tool, and health experts say it should only be considered if other methods fail. If a smoker does switch completely to vaping, it may lower some toxin exposure (since there’s no combustion), but the ultimate goal should be to quit nicotine entirely.
Bottom line
Neither vaping nor smoking is harmless. Cigarettes expose the user to thousands of deadly chemicals, making smoking a leading cause of cancer, heart disease and lung disease. Vaping cuts out much of the tobacco smoke, but still delivers addictive nicotine along with other toxins. Current evidence suggests vaping is less dangerous than smoking, but it is not safe. Experts emphasize that non-smokers (especially youth and pregnant women) should avoid e-cigarettes altogether. For smokers, the healthiest choice is to quit all tobacco and nicotine products. If quitting is difficult, switching completely to vaping might reduce some harms, but both smoking and vaping users are urged to seek help from healthcare professionals. In the end, quitting is best for everyone’s health.
References
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U.S. Surgeon General Report on E-Cigarette Use Among Youth and Young Adults (2016)
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CDC Office on Smoking and Health – Health Effects of Cigarette Smoking
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U.S. Preventive Services Task Force (USPSTF) Tobacco Use Recommendations
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American Cancer Society – E-Cigarette and Vaping Health Impact
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CDC: Quick Facts on the Risks of E-cigarettes for Young People
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World Health Organization (WHO): Tobacco and Electronic Nicotine Delivery Systems
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U.S. Department of Health and Human Services: Smoking Cessation Report (2020)
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American Heart Association Scientific Statements on Tobacco and Vaping
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Journal of Clinical Investigation: Cardiovascular Effects of Vaping