“We now know that cigarettes and vapes both expose the lungs to harmful substances,” says Fan Z. Caprio, MD, a vascular neurologist at Northwestern Medicine. “While the devices may look different, the health risks can overlap and sometimes be just as serious.”

What Are E-Cigarettes?

E‑cigarettes come in many shapes and sizes, including disposable devices, vape pens and pod‑based systems. Some are designed to resemble USB drives or small electronic devices, which can make them easy to conceal.

Although designs vary, most e‑cigarettes work in a similar way. A battery heats a liquid (often called e-liquid or vape juice) and turns it into an aerosol that is inhaled into the lungs. This liquid usually contains:

• Nicotine
• Flavoring chemicals
• A base liquid, often propylene glycol or vegetable glycerin

When these liquids are heated, they can chemically change and produce potentially harmful substances, including known carcinogens, such as formaldehyde and acetaldehyde.

E‑cigarettes do not burn tobacco like regular cigarettes, but that does not make them harmless. The aerosol they produce can still deliver chemicals deep into the lungs.

What Science Shows

E‑cigarettes are newer than traditional cigarettes, so research is still ongoing. However, several findings point to health risks:

• Many vaping products deliver high levels of nicotine, which is addictive and can make quitting harder.
• Vaping exposes the lungs to heated chemicals and ultrafine particles.
• Research has linked vaping to:
• Changes in lung function and structure
• Heart failure
• Blood vessel damage
• Increased stroke risk

Smoking, Vaping and the Stroke Link

“The link between cigarettes and increased risk for stroke has been well established,” says Dr. Caprio. “There are several mechanisms by which that happens.”

Studies suggest that both smoking and vaping can expose the body to substances that may affect cardiovascular health over time. These effects from vaping may be more pronounced when combined with other factors like smoking tobacco products or high blood pressure.

“These toxins can cause inflammation and damage in the lungs and the blood vessels, which then contribute to hardening of blood vessels,” says Dr. Caprio.

When blood vessels are damaged, it can reduce blood flow and contribute to plaque buildup over time, increasing stroke risk.

What Happens in the Lungs When You Vape

When you vape, the aerosol carries microscopic particles that can stick to lung tissue. Over time, repeated exposure can cause:

• Inflammation and swelling of lung tissue
• Damage to the air sacs (alveoli) that help oxygen enter the blood
• Reduced lung flexibility and strength

This damage can be worse for people who vape frequently or who already have lung disease.

What Are You Really Inhaling?

Many people think vaping is “just water vapor.” This is not true. Vaping products often contain:

• Nicotine (typically at high levels)
• Chemical flavorings, such as diacetyl, which has been linked to bronchiolitis obliterans (“popcorn lung”)
• Ultrafine particles
• Volatile organic compounds, such as benzene, toluene and xylene
• Heavy metals, such as nickel and lead, from device components
• Tetrahydrocannabinol (THC) and cannabidiol (CBD) oils, both active ingredients in marijuana

Once heated, these substances enter the lungs and bloodstream within seconds.

Vaping can also expose users to a complex and largely unregulated mix of chemicals, many of which have uncertain long-term health effects. One study found nearly 2,000 chemicals in vaping liquids and aerosols not disclosed by the manufacturers.

For comparison, traditional cigarettes contain about 600 ingredients and produce more than 7,000 chemicals when burned, at least 69 of which are known to cause cancer.

Is Vaping Safer Than Smoking?

A better question than “Is vaping safer?” is “How do the risks differ?”

Traditional cigarettes create smoke through burning, while e‑cigarettes create aerosols using heat. Both methods expose the lungs to substances that can affect lung and cardiovascular health.

While vaping may lower exposure to some toxins found in cigarettes, it can also introduce new toxins and risks, many of which are still being studied.

“Because e-cigarettes are not fully regulated, we don’t yet understand the long-term health consequences,” says Matthew B. Potts, MD, a neurosurgeon at Northwestern Medicine.

While e-cigarettes were developed as an alternative to traditional cigarettes, this does not mean they are safe, especially with long‑term or frequent use.

Lung Problems Linked to Vaping

Pulmonologists (lung doctors) and surgeons are seeing lung injuries linked to vaping, including:

• Worsening asthma
• Lung tissue scarring
• EVALI (e‑cigarette or vaping‑associated lung injury)

EVALI can include several patterns of lung injury, such as severe lung inflammation and respiratory failure, and has been strongly linked to certain additives, including vitamin E acetate.

EVALI symptoms may include:

• Chest pain
• Cough
• Shortness of breath
• Rapid heartbeat
• Nausea and vomiting
• Fever

Some patients require oxygen support or hospitalization.

When To Seek Medical Care

Anyone who uses e‑cigarettes regularly or long-term should tell their doctor. This helps guide care screening and risk reduction.

Get medical help right away if you vape and notice:

• Chest pain
• Trouble breathing
• Ongoing cough
• Fever or chills
• Sudden fatigue
• Sudden shortness of breath

These symptoms may signal lung injury or infection.

Can Lung Damage From Vaping Be Reversed?

Some vaping‑related lung problems may improve after quitting. Inflammation can decrease, and breathing may get easier over time as the lungs begin to recover.

However, repeated or long-term exposure to vaping aerosols can lead to permanent scarring of lung tissue. Scar tissue does not heal, which is why quitting early is so important. The longer you vape, the greater the risk of lasting lung damage.

Why Teens and Young Adults Are at Higher Risk

The lungs and brain continue developing into the mid‑20s. Nicotine exposure during this time can:

• Increase risk of addiction
• Affect brain development
• Lead to heavier and longer-term use

Disposable e‑cigarettes make vaping easier to hide and harder to track, raising the risk of frequent use.

Vaping and Chronic Lung Conditions

For people with asthma, chronic obstructive pulmonary disease (COPD) or other breathing problems, vaping can:

• Trigger flare-ups
• Increase inflammation
• Reduce symptom-free days

Even occasional vaping can worsen breathing.

Does Vaping Increase Cancer Risk?

Scientists are still studying whether vaping increases cancer risk. While e‑liquids often start with a limited number of ingredients, heating those ingredients can create additional chemicals not listed on product labels.

Laboratory testing has identified hundreds of chemicals in some vaping aerosols, including substances linked to cancer. Although the full risk is not yet known, experts agree that breathing heated chemicals into the lungs is not without risk.

“Inhaling any chemical into the lungs carries risks, especially over time,” says Dr. Potts.

Is Vaping a Safe Way To Quit Smoking?

Some people try vaping as a way to stop smoking cigarettes, but many end up using both products.

Doctors recommend these methods instead:

• Nicotine replacement therapy (patches, gum or lozenges)
• Prescription medications
• Behavioral counseling and support programs

Reduce Your Risk of Stroke and Lung Disease

Because smoking and vaping are known modifiable risk factors for stroke, quitting is important for prevention.

“Stroke prevention is the best way to treat a stroke,” says Dr. Caprio. “Every patient is different, so I try to spend the time to talk to patients and discuss their individual factors.”

In addition to quitting smoking and vaping, you can reduce your risk of stroke by:

• Eating a healthy diet low in saturated fat and high in fiber
• Exercising regularly (healthy target: 150 minutes of moderate aerobic activity or 75 minutes of vigorous activity per week)
• Managing blood pressure, cholesterol and diabetes
• Maintaining your regular care with a primary care physician

“When it comes to a stroke, time is critical,” says Dr. Potts. “You need to call 911 right away.”

Know the signs so you can B.E. F.A.S.T.