TL;DR:
- Vaping exposes lungs to far fewer toxic chemicals than smoking and doesn’t produce tar or carbon monoxide. For adults who switch completely from smoking it’s much less harmful—but not harmless. (NHS)
- Short term, vaping can cause throat irritation, coughing and increased airway resistance. Research suggests effects on the lungs’ immune defences (like alveolar macrophages and cilia), possibly raising infection risk. (NCBI)
- Long term, evidence is still developing. Observational research links vaping to more bronchitic symptoms/wheeze, with ongoing debate around COPD. Many vapers are current or ex-smokers, making causation hard to prove. (Thorax Journal)
- The 2019 US “EVALI” outbreak was linked to vitamin E acetate in illicit THC vapes, not UK-regulated nicotine e-liquids. (CDC)
- “Popcorn lung” (bronchiolitis obliterans) is not caused by UK-regulated vapes; diacetyl is banned as an ingredient in UK nicotine e-liquids. (NHS Debunking Vaping Myths)
- For non-smokers and under-18s: don’t vape. For adult smokers, fully switching to regulated vaping products reduces lung exposure to toxins and can improve symptoms versus continued smoking. (Public Health England)
What’s Actually Going Into Your Lungs When You Vape?
E-liquids typically contain propylene glycol, vegetable glycerine, nicotine, and flavourings. When heated, they form an aerosol. Unlike smoking, there’s no combustion—so no tar or carbon monoxide. However, small amounts of carbonyls (like formaldehyde, acrolein) and trace metals from coils can appear, especially at high power settings. (UK Gov Review)
How the Lungs React in the Short Term
Irritation, cough, and airway resistance: Studies show transient airway irritation and increased resistance after vaping, though spirometry (FEV₁) is often unchanged. (NCBI Study)
Immune defences: Lab data suggests vaping aerosols may impair alveolar macrophage function and blunt antimicrobial activity, possibly increasing infection risk. (Nature Scientific Reports)
Respiratory Symptoms and Daily Life
Research has linked vaping (especially in young people) with cough, phlegm, and wheeze. These are associations, not proof, but the consistency across studies is concerning. (Thorax Journal)
Asthma and COPD
- Asthma: Vaping can irritate hyper-reactive airways, potentially triggering wheeze or cough. Clinicians advise avoiding vaping where possible.
- COPD: Some studies report higher odds of COPD in vapers, though smoking history makes this hard to untangle. Switching completely from smoking to vaping can improve symptoms, but dual-use largely cancels the benefit. (MDPI Journal)
EVALI Explained
In 2019, the US saw cases of severe lung injury (“EVALI”). Investigations linked this to vitamin E acetate in illicit THC cartridges. UK-regulated nicotine vapes were not implicated. (CDC)
“Popcorn Lung” Myth
Popcorn lung (bronchiolitis obliterans) was linked to high workplace diacetyl exposure. UK law bans diacetyl in e-liquids, and there are no confirmed vaping-related cases. Cigarettes contain more diacetyl than tested vape liquids ever did. (NHS)
Second-Hand Vapour
Evidence suggests second-hand vapour is far less risky than second-hand smoke. Still, avoid vaping near children or people with lung conditions. (NHS)
Vaping vs Smoking: The Trade-Off
Smoking fills lungs with tar and carbon monoxide, driving COPD, cancer and emphysema. Vaping cuts toxicant exposure drastically, with biomarkers showing much lower toxin levels in exclusive vapers. (OHID Evidence Update)
Practical Tips for Adult Smokers Who Vape
- Avoid dual-use—each cigarette undermines lung benefits. (Thorax Study)
- Use UK-regulated products only. (NHS Guidance)
- Find the right nicotine strength—too low means over-puffing, too high feels harsh. (NHS Vaping Advice)
- Keep coils wet, avoid “dry puffs” to reduce aldehyde emissions. (Nature Research)
- If you have asthma or COPD, consult your GP—non-inhaled nicotine options may be safer.
FAQs
Is vaping bad for your lungs?
Less harmful than smoking, but not harmless. (NHS)
Does vaping cause lung cancer?
No direct evidence, but some carcinogens are present at much lower levels than smoking. (OHID)
Is “popcorn lung” a risk?
No. Diacetyl is banned in UK e-liquids. (NHS)
Does second-hand vapour harm others?
No evidence of significant harm so far. (NHS)
Research Resources
- NHS: Using e-cigarettes to quit smoking
- NHS: Vaping myths debunked
- OHID/UK Government Evidence Update (2021)
- Cochrane Review (2025)
- Thorax Journal: Vaping and bronchitic symptoms
- CDC: EVALI outbreak
Disclaimer: This article is for informational purposes only and should not replace personalised medical advice. If you have new or worsening lung symptoms, consult a GP or respiratory specialist.
