The most common cause of vape-related sickness is nicotine overdose, commonly called “nic sick”. Symptoms include nausea, dizziness, headache, sweating, rapid heartbeat, and (in more serious cases) vomiting, tremors and confusion. Nic sick happens when nicotine absorbed exceeds the body’s tolerance, which is most common in new vapers, vapers who switched to a stronger product, chain vapers who do not pace themselves, or anyone vaping on an empty stomach when nicotine absorption is faster and effects more intense.

Several other factors can also cause vape-related sickness. Dehydration from PG and VG drawing moisture from the body causes headaches, dizziness and nausea. Chain vaping (rapid frequent puffs without breaks) builds up nicotine levels faster than the body can clear them. Sensitivity to PG (a mild allergy-like response) causes nausea and throat irritation in some users. Low-quality or counterfeit e-liquids may contain undisclosed compounds that cause sickness; this is one reason to buy only from registered UK retailers.

EVALI (e-cigarette or vaping use-associated lung injury) is the serious condition that received heavy media coverage from 2019 onwards in the US. EVALI symptoms can include severe shortness of breath, dry cough, chest pain, fever, nausea and vomiting, often requiring hospitalisation. EVALI is rare in the UK: the US outbreak was linked to vitamin E acetate added to illicit THC vape products, an ingredient banned in UK TPD-compliant e-liquids. Cancer Research UK confirms there is no good evidence that legal UK e-cigarettes cause lung disease. If you experience severe respiratory symptoms after vaping (especially from grey-market or illicit products), seek immediate medical care.

Recognising “nic sick” and what to do

Phase 1 symptoms (15 minutes to 1 hour after exposure): nausea, dizziness, headache, sweating, rapid heartbeat, hand tremors, salivation, anxiety. Phase 2 symptoms (30 minutes to 4 hours, after the stimulant phase): weakness, low blood pressure, slow heartbeat, fatigue, possible diarrhoea. Both phases together typically resolve in 1-4 hours for mild to moderate cases. What to do: stop vaping immediately, drink water (small sips), eat a small meal or snack if you can keep food down, rest in fresh air, do not lie flat if dizzy. For severe symptoms (seizures, breathing difficulty, persistent vomiting, very rapid heartbeat or loss of consciousness) call 999 immediately.

Why nicotine strength matters and how to step down

The UK legal maximum is 20mg/ml nicotine salt. For users transitioning from cigarettes, 20mg/ml typically matches a smoker’s daily nicotine intake. For non-smokers, never-smokers or anyone reducing nicotine, 20mg/ml is often too strong and causes regular nic sick episodes. Solution: step down. Lost Mary, Elf Bar and other major UK brands offer 10mg/ml prefilled pods. Refillable kits offer 0-20mg/ml in 2mg or 5mg increments via bottled nic salts. A typical stepdown over 3-6 months: 20mg/ml > 10mg/ml > 5mg/ml > 0mg. Most vapers find symptoms of nicotine overconsumption disappear once they reach the right strength for their tolerance.

Why EVALI is rare in the UK and which products to avoid

EVALI was the cluster of severe vape-related lung injuries reported primarily in the US from 2019 onwards. The CDC investigation identified vitamin E acetate as the strongest single cause, used as a thickening agent in illicit THC vape cartridges. Vitamin E acetate is banned from all UK TPD-compliant e-liquids. The UK has not seen an EVALI outbreak. Risk factors that do still apply in the UK: counterfeit or grey-market vape products that may contain undisclosed ingredients including vitamin E acetate, illicit THC vapes (illegal in the UK), and any cartridge sold by unregistered sellers at suspiciously low prices. Always buy from a Companies House registered UK retailer with verifiable authentication codes.

For UK vapers experiencing recurring sickness from their vape, the five habits below typically prevent further episodes. None require stopping vaping.

If you experience severe vape-related symptoms (persistent vomiting, breathing difficulty, chest pain, confusion, seizures or loss of consciousness) call 999 immediately. For ongoing mild symptoms that persist despite habit changes, see your GP for assessment. Be honest about vape use and product details; if you suspect a counterfeit or grey-market product, bring the packaging. NHS clinicians treat vape-related symptoms as a routine matter and can refer to specialist services if needed.