As cannabis use among youth rises in Canada — and THC potency reaches record highs — emergency departments are seeing a surge in cases of a once-rare condition: cannabis hyperemesis syndrome (CHS).
Characterized by relentless vomiting, abdominal pain and temporary relief through compulsive hot showers or baths, CHS is increasingly affecting adolescents and young adults. Yet few people — including many clinicians — know it exists.
Canada ranks among the highest globally for youth cannabis use, with 43 per cent of 16-19-year-olds reporting use in the past year. Usage peaks among those 20–24 years, with nearly half (48 per cent) reporting past-year use.
This rise in regular, heavy use coincides with a 400 per cent increase in THC potency since the 1980s. Strains with THC levels above 25 per cent are now common. As cannabis becomes more potent and accessible, clinicians are seeing more cases of CHS, a condition virtually unheard of before 2004.
CHS unfolds in three phases:
Prodromal phase: Nausea and early morning discomfort begin. Users increase cannabis consumption, thinking it will relieve symptoms.
Hyperemetic phase: Intense vomiting, dehydration and abdominal pain follow. Hot showers or baths provide temporary relief — a hallmark of CHS.
Recovery phase: Symptoms resolve after stopping cannabis entirely.
Diagnosis is often delayed. One reason is because CHS mimics conditions like gastroenteritis or eating disorders, leading to costly CT scans, MRIs and gastric emptying tests. One telltale sign — compulsive hot bathing — is frequently overlooked, despite its strong diagnostic value.
Youth face unique risks. The brain continues to develop until about age 25, and THC exposure during this critical window can impair cognitive functions like memory, learning and emotional regulation. Heavy cannabis use is associated with heightened risks of anxiety, depression, psychosis and self-harm.
Edit, the link in the article goes to this study:
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2796355
Results There were 12 866 ED visits for CHS from 8140 individuals during the study. Overall, the mean (SD) age was 27.4 (10.5) years, with 2834 individuals (34.8%) aged 19 to 24 years, 4163 (51.5%) females, and 1353 individuals (16.6%) with a mental health ED visit or hospitalization in the 2 years before their first CHS ED visit. Nearly 10% of visits (1135 visits [8.8%]) led to hospital admissions. Monthly rates of CHS ED visits increased 13-fold during the 7.5-year study period, from 0.26 visits per 100 000 population in January 2014 to 3.43 visits per 100 000 population in June 2021. Legalization was not associated with an immediate or gradual change in rates of ED visits for CHS; however, commercialization during the COVID-19 pandemic period was associated with an immediate increase in rates of CHS ED visits (incidence rate ratio [IRR], 1.49; 95% CI, 1.31-1.70). During commercialization, rates of CHS ED visits increased more in women (IRR, 1.49; 95% CI, 1.16-1.92) and individuals older than the legal age of cannabis purchase (eg, age 19-24 years: IRR, 1.60; 95% CI, 1.19-2.16) than men (IRR, 1.08; 95% CI, 0.85-1.37) and individuals younger than the legal age of purchase (IRR, 0.78; 95% CI, 0.42-1.45).
The problem is, what Health Canada once labelled as "heavy use" is pretty much normal use these days. Daily use, or using multiple times a day, is very common.
If people (and teens) were only consuming once in a while, I doubt we'd be in this mess.
They consume often, partly because they've been told "it helps with XYZ", so they self-medicate, which leads to greater problems. But also because they believe it's "safe".
Single cannabis use can also lead to acute impairment and puts stresses on the body. I've never heard of someone getting in a car and killing someone because they were impaired on having chocolate that afternoon. 😆
You are being down voted but this exact thing happened to somebody I know. The repeal of criminalization, without a better education plan, gave them the idea that "Oh its fine now". They became addicted to smoking it, spent all day every day just hitting a bong. Stopped working, had to repeat a year at uni to get courses on track. They've had to completely abstain, or they fall back into the spiral. Some people get addicted to alcohol, some its another drug entirely.
I'm being downvoted because addicts have to defend and justify their addiction, unfortunately.
I had a family member who also went through the same. They developed psychosis (Cannabis-induced depersonalization-derealization disorder) through daily use of cannabis, and ended up needing to get treatment after their life went downhill.
Stopped once the weed stopped, but it was an alarming transition, and not an easy addiction to break.
They only became hooked once legalization came into effect, since it was accessible from anywhere.
I've already corrected your misinterpretation of the studies on several occasions, so there's no need to continue to belabour the point. If you want to argue about it to the authors of those studies, I'm sure they'd love to hear from you.
This is not a "war on drugs", but a public health concern. You're free to harm yourself however you like. But the public, especially our youth, should be better informed of the risks, especially while the chatter about cannabis being "safe" is still being thrown about casually.
I had to check if we were in the same family/circle. Besides the one situation I mentioned, what you described happened happened to a family friend also. Quite a scary time for those around the person that didn't know what was happening to them (because isolation had led to less interaction), but luckily the ones that got hints took them in to make sure they were OK. And turned out it was bad psychosis and required a few weeks hospitalization.
I'm a let people do what they want guy, but claiming marijuana is harmless is dangerous.