What are the short-term health effects of vaping compared to smoking?
Executive summary
Short-term harms from vaping and smoking overlap (nicotine effects, airway irritation, increased heart rate and blood pressure), but major health authorities and recent reviews find vaping typically exposes users to fewer combustion-derived toxicants than cigarettes and may be less harmful in the short term for adult smokers who fully switch (CDC; Our World in Data; Johns Hopkins) [1] [2] [3]. However, vaping still produces acute respiratory effects, nicotine dependence, and cardiovascular responses similar in direction to smoking; evidence is mixed on magnitude and many studies are observational or short-term [4] [5] [6].
1. Short-term respiratory effects: irritation, coughing and airway resistance
Both vaping and smoking can cause immediate airway irritation, coughing and measurable changes in lung function; studies report that just 5 minutes of vaping increased peripheral airway resistance in some trials, while cigarette smoke is a long-established acute irritant that reduces lung function—overall, vaping produces acute respiratory effects but usually lacks the broad suite of combustion products found in tobacco smoke [4] [5] [7].
2. Cardiovascular responses: nicotine-driven increases in heart rate and blood pressure
Nicotine in both products raises heart rate and diastolic blood pressure acutely via sympathetic stimulation; a meta-analysis found vaping increases resting heart rate and diastolic BP similar to smoking but perhaps less pronounced—most reviewers attribute much of these acute cardiovascular effects to nicotine rather than the delivery method [4] [5].
3. Toxicant exposure: fewer combustion chemicals in vapes, but not harmless
Clinical biomarker studies and reviews report that exclusive e‑cigarette users have lower levels of many urinary carcinogens than smokers, reflecting the absence of tobacco combustion products; nevertheless, vapes can deliver harmful substances—including aldehydes like acrolein and a wide range of poorly characterized flavoring chemicals—so reduced toxicant profile does not equal safe [5] [8].
4. Addiction and population impact: nicotine dependence and youth risk
Vaping commonly delivers nicotine and sustains dependence; public‑health bodies warn that e‑cigarettes attract young non‑smokers and can make them more likely to later smoke, creating a new cohort addicted to nicotine even if individual vaping carries lower short‑term toxicant exposure than smoking [1] [2] [9].
5. Relative risk framing: less harmful for smokers who fully switch, but evidence limits remain
Major health organizations and recent analyses present a qualified position: for adults who smoke and completely switch to vaping, short‑term harm is likely lower than continued smoking because of reduced exposure to combustion toxins; yet scientists emphasize incomplete understanding of which vape components cause which effects and warn that many studies are observational or short‑term, limiting causal certainty [1] [2] [10].
6. Conflicting findings and important caveats in the literature
Some studies and reviews underscore that both vaping and smoking are associated with higher rates of respiratory disease (COPD) and other harms, with the effect larger for cigarettes; other work highlights case reports and outbreaks (EVALI) and device failures that produced acute severe injuries—these divergent findings reflect heterogeneity in products, user behavior, dual use (vaping plus smoking), and study design [3] [7] [10].
7. What the evidence does not settle: long‑term trajectories and product variability
Available sources stress that long‑term effects of vaping remain uncertain because the products are new and highly variable; no source in the provided reporting settles decades‑long risks, and many analyses call attention to unknowns about specific flavor chemicals, populational shifts (youth uptake), and the net public‑health tradeoffs of vaping as a cessation tool versus a new addiction pathway [5] [11] [9].
8. Practical takeaway for readers weighing short‑term effects
If an adult smoker fully replaces combustible cigarettes with e‑cigarettes, current evidence suggests a likely reduction in short‑term exposure to many harmful combustion products and possibly lower short‑term harm; however, vaping still causes acute respiratory irritation, raises heart rate and blood pressure via nicotine, sustains addiction, and carries nontrivial risks—public‑health bodies recommend evidence‑based cessation treatments first and warn against vaping among non‑smokers and youth [1] [4] [6].
Limitations: most cited studies are short term or observational; product heterogeneity and evolving devices mean results may not generalize across all vapes; available sources do not settle long‑term outcomes [5] [10].