Vaping can cause damage to your lungs, heart, brain, immune system, mouth, and reproductive health. While often marketed as a safer alternative to cigarettes, e-cigarettes expose you to nicotine, heavy metals, and toxic chemicals that affect nearly every major organ system. Some of these effects are immediate, others build over months or years, and a few can be life-threatening.
Serious Lung Injury
The most dramatic example of vaping-related lung damage is EVALI, short for e-cigarette or vaping product use-associated lung injury. Between 2019 and early 2020, the CDC recorded 2,807 hospitalizations and 68 confirmed deaths from EVALI across all 50 states. Symptoms include cough, chest pain, shortness of breath, nausea, vomiting, fever, and weight loss. The primary culprit was vitamin E acetate, an oily additive used to cut THC-containing cartridges. When researchers tested fluid from the lungs of 51 EVALI patients, 48 of them had vitamin E acetate present. None of the healthy control subjects did.
The EVALI outbreak was largely tied to black-market THC cartridges, not commercial nicotine products. But that doesn’t mean standard vaping is harmless to your lungs. E-cigarette aerosol contains chemicals that can irritate and inflame lung tissue over time, and the heating element itself introduces metals directly into what you inhale.
Heavy Metals in Every Puff
The coil inside a vape device heats the liquid to create aerosol. That coil is typically made from nichrome or kanthal, alloys containing iron, chromium, aluminum, and nickel. As the coil heats up, tiny amounts of these metals vaporize and enter the aerosol you breathe. Researchers have detected silver, aluminum, chromium, copper, iron, nickel, and zinc in e-cigarette emissions. These metals accumulate in the body over time, and chronic exposure to several of them is linked to inflammation, cellular damage, and cancer risk.
Formaldehyde From Overheated Liquid
When e-liquid overheats, its base ingredients break down into formaldehyde, a known carcinogen. How much formaldehyde you’re exposed to depends heavily on voltage. At 3.3 volts, researchers measured about 3.4 micrograms per 10 puffs. At 5.0 volts, that number jumped to over 718 micrograms per 10 puffs, a more than 200-fold increase.
Most users won’t deliberately vape at the highest settings because the taste becomes harsh and unpleasant, a sensation called a “dry puff.” In one study, 88% of participants could detect dry puffs at or below 4.2 volts, and at 4.0 volts the formaldehyde level was about 20 micrograms per 10 puffs. Still, devices with adjustable power settings, worn-out coils, or low liquid levels can all push temperatures into the danger zone without the user realizing it.
Cardiovascular Effects
Nicotine-containing e-cigarettes cause immediate, measurable changes to your cardiovascular system. A meta-analysis published in the European Heart Journal Open found that vaping with nicotine increased heart rate by about 5 beats per minute compared to baseline, and that elevated heart rate persisted 30 minutes after use. Arterial stiffness, a key marker of cardiovascular stress, also rose significantly right after vaping. Stiffer arteries make your heart work harder and raise long-term risk for heart disease and stroke.
Interestingly, when researchers compared nicotine e-cigarettes to traditional cigarettes, they found no significant difference in how much each impaired blood vessel function. In other words, vaping with nicotine appears to stress your blood vessels in a similar way to smoking.
Your Lungs’ Immune Defense Takes a Hit
Deep inside your lungs, specialized immune cells called alveolar macrophages act as a first line of defense. They engulf inhaled pathogens and particles, then coordinate the broader immune response. In vapers, these cells look and behave differently than in both nonsmokers and smokers.
Researchers found that vapers’ macrophages contained unusual debris-filled structures inside them that were completely absent in nonsmokers and smokers. At the gene level, vapers had 124 genes uniquely turned down compared to the other groups. Key signaling proteins that recruit other immune cells to fight infection were also suppressed in the airway lining of vapers. The overall picture suggests that vaping may leave your lungs less able to detect and respond to infections, potentially making you more vulnerable to pneumonia and other respiratory illnesses. Notably, these immune changes were more pronounced in vapers than in cigarette smokers.
Nicotine and the Developing Teen Brain
The prefrontal cortex, the part of the brain responsible for decision-making, impulse control, and sustained attention, is one of the last brain regions to fully mature. It continues developing into your mid-20s. Nicotine exposure during adolescence disrupts this process in ways that don’t happen with adult exposure.
In adolescents, nicotine changes how nerve cells in the prefrontal cortex communicate. It increases the number of nicotine-sensitive receptors and alters the balance between excitatory and inhibitory signaling. It even physically reshapes neurons, increasing both the length of their branches and the density of connection points. Some of these changes reverse after quitting. Receptor levels return to normal within about five weeks. But other changes stick around. Receptors that regulate the release of the brain’s main excitatory chemical become persistently reduced after adolescent nicotine exposure, and this lasting change has been linked to impaired attention performance in animal studies.
Gum Disease and Oral Health
Vaping takes a toll on your mouth, too. Both e-cigarette and cigarette users show higher rates of periodontal (gum) disease compared to nonsmokers. E-cigarette aerosol may reduce blood flow to the gums and suppress local immune defenses, making gum tissue more susceptible to inflammation and breakdown. The heavy metals in vapor, including lead, nickel, and chromium, can also be directly toxic to gum tissue.
Beyond the gums, vaping reshapes the bacterial community in your mouth. Research shows that e-cigarette users have increased colonization by disease-causing bacteria and reduced microbial diversity overall. This shift toward more harmful bacteria can amplify inflammatory responses and raise the risk of oral infections. Dry mouth, another common complaint among vapers, further compounds these problems by reducing saliva’s natural protective effects.
Risks During Pregnancy
Nicotine in any form is harmful during pregnancy. It can damage both the developing brain and lungs of a fetus. The CDC states plainly that e-cigarettes and other nicotine-containing products are not safe during pregnancy. Some of the flavoring chemicals used in e-liquids may pose additional risks, though the specific effects of individual flavorings on fetal development are still being studied. The bottom line is that switching from cigarettes to vaping during pregnancy does not eliminate the danger that nicotine poses to fetal development.
Diacetyl and “Popcorn Lung”
Diacetyl is a flavoring chemical that gives a buttery taste to some e-liquids. Inhaling diacetyl in large amounts is the established cause of bronchiolitis obliterans, commonly called popcorn lung, a condition where the tiny airways in the lungs become scarred and narrowed. The disease was first identified in workers at microwave popcorn factories who inhaled diacetyl-laden air daily. Cleveland Clinic lists vaping as a potential route of diacetyl exposure and includes e-cigarettes among substances that can increase popcorn lung risk. While confirmed cases of popcorn lung specifically caused by vaping remain rare, the presence of a known lung toxin in something you inhale repeatedly is a legitimate concern, particularly for heavy, long-term users.