Most CHS patients have used cannabis daily for over 2 years, and the condition is increasingly common as product potency rises, yet many patients are skeptical that cannabis causes their symptoms.
Emergency physicians, gastroenterologists, primary care providers, heavy cannabis users
What the researchers found
This comprehensive review found that 40-80% of cyclic vomiting syndrome (CVS) patients use cannabis. CHS is characterized by daily or near-daily cannabis use for over 2 years, cyclic vomiting, and hot-water bathing for relief. The distinction from CVS is challenging, as hot bathing is also reported by ~50% of CVS patients. Key treatment barriers include patient skepticism about cannabis causing symptoms, perceived benefits of cannabis, and lack of effective alternatives. Cannabis abstinence remains the cornerstone of CHS management.
Why it matters
As cannabis potency has risen dramatically, CHS is becoming more common and is a significant contributor to emergency department visits and hospitalizations. The paradox that an antiemetic substance causes vomiting remains clinically challenging.
The numbers in context
40-80% of CVS patients use cannabis; most CHS patients: daily use for 2+ years; hot bathing reported by most CHS patients and ~50% of CVS patients; cannabis has documented antiemetic properties yet causes hyperemesis with chronic heavy use
How the study worked
Comprehensive narrative review of cannabis use patterns in the US and their relationship to CHS and CVS, including diagnostic criteria, pathophysiology, management, and knowledge gaps.
What this study cannot tell us
Narrative review without systematic methodology. CHS vs CVS distinction remains debated. Exact prevalence of CHS is unknown. No randomized trials of CHS-specific treatments beyond cannabis cessation.
How to read the evidence
Moderate: thorough narrative review synthesizing clinical evidence, but without systematic methodology.
When this study was published
2025 review article
The bigger picture
CHS represents an ironic consequence of cannabis normalization: a substance known for reducing nausea becomes the cause of severe, recurrent vomiting in heavy users, and the very patients affected are often the last to accept this connection.
Questions still open
- Will CHS incidence continue to rise with increasing THC potency?
- Are there pharmacological treatments that could help CHS patients who struggle with cannabis cessation?
Read the original research
Cannabis use patterns and association with hyperemesis: A comprehensive review.
Neurogastroenterology and motility, 37(3), e14895
Citation
Hasler, William L; Alshaarawy, Omayma; Venkatesan, Thangam. (2025). Cannabis use patterns and association with hyperemesis: A comprehensive review.. Neurogastroenterology and motility, 37(3), e14895. https://doi.org/10.1111/nmo.14895
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