Rising Incidents of Cannabis-Induced Vomiting Among Youth Leading to ER Visits

As cannabis consumption among young people increases in Canada, and with THC levels reaching record highs, emergency departments are experiencing a notable rise in cases of cannabis hyperemesis syndrome (CHS), a condition characterized by severe, persistent nausea and vomiting. CHS was once rare, but its prevalence is growing, especially in adolescents and young adults. This trend coincides with a significant surge in heavy cannabis use, driven by legalization and the availability of more potent strains containing THC levels above 25%.

Cannabis hyperemesis syndrome progresses through three stages: initially, prodromal with mild nausea and discomfort; then, a hyperemetic phase involving intense vomiting, dehydration, and abdominal pain, with temporary relief often sought through hot showers or baths—an identifying feature of CHS; finally, recovery occurs after abstinence from cannabis. Unfortunately, diagnosis is frequently delayed because its symptoms resemble other conditions like gastroenteritis or eating disorders, and the hallmark hot bathing behavior is often overlooked.

Younger individuals are particularly vulnerable. Since the brain continues developing until about age 25, exposure to high THC levels can impair cognitive functions including memory, learning, and emotional regulation. Heavy use also correlates with increased risks of anxiety, depression, psychosis, and self-harm. Consequently, some youth approach cannabis as a form of self-medication for mental health issues, further complicating diagnosis as many are hesitant to disclose their use due to stigma or legal concerns. Interestingly, CHS can be misdiagnosed as bulimia nervosa, given the vomiting and weight loss, although CHS-related vomiting is involuntary, and patients often return to normal eating and bathing routines during symptom-free periods.

The increase in CHS cases strains the healthcare system, with emergency visits rising significantly post-legalization. Repeated ER visits, missed schooling or work, and emotional distress are common, and in rare cases, dehydration can lead to kidney failure. Current antinausea treatments often offer limited relief, with some topical remedies or low-dose medications providing only temporary help unless cannabis use is stopped.

The most effective solution remains abstinence from cannabis. However, for youth using cannabis to cope with mental health conditions, stopping can induce withdrawal and emotional distress. Therefore, harm reduction strategies—such as gradual dose reduction, mental health support, and empathetic, stigma-free communication—are essential. Healthcare providers should routinely screen young patients with cyclic vomiting for cannabis use and hot bathing behaviors.

Public health initiatives must also emphasize education—delivering clear, accessible information on CHS, its symptoms, and the importance of seeking help. Integrating CHS awareness into school health programs, pediatric training, and cannabis screening protocols is crucial. As cannabis legalization progresses, it is vital to inform youth and their caregivers about the full scope of health risks associated with chronic use, including the preventable yet growing occurrence of cannabis hyperemesis syndrome.