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Study breakdown

What pharmacists and doctors need to know about cannabinoid hyperemesis syndrome

ReviewPreliminary evidence
The takeaway

Long-term cannabis use can trigger a condition called cannabinoid hyperemesis syndrome, marked by severe nausea, vomiting, and compulsive hot water bathing.

Read this if you use cannabis regularly and experience unexplained nausea or vomiting, or if you want to understand this underrecognized condition.

CHS is considered underrecognized and underdiagnosed in emergency departments

What the researchers found

This review described cannabinoid hyperemesis syndrome (CHS), a condition associated with long-term cannabis use characterized by cycles of severe nausea and vomiting without another identifiable cause. A distinctive feature of CHS is that patients develop compulsive hot water bathing behavior, which temporarily relieves symptoms.

Patients with CHS frequently visit emergency departments for relief but are often subjected to extensive diagnostic workups before receiving a correct diagnosis. The authors concluded that CHS is likely underrecognized and underdiagnosed, particularly in emergency settings.

Why it matters

As cannabis use has become more common, clinicians have increasingly recognized CHS as a distinct clinical entity. Awareness of this condition can help prevent unnecessary and invasive diagnostic procedures in patients whose symptoms have a straightforward explanation.

The numbers in context

No large-scale prevalence data were reported. The review synthesized findings from published case reports and small case series available through 2013.

How the study worked

The authors conducted a literature review using PubMed to identify published reports and case series describing cannabinoid hyperemesis syndrome, its clinical features, and management approaches.

What this study cannot tell us

This was a narrative review based primarily on case reports and small series, not controlled studies. The exact prevalence of CHS remained unknown at the time of publication. The mechanisms behind compulsive hot bathing behavior were not well understood.

How to read the evidence

Narrative review of case reports and small series, without systematic methodology or controlled data.

When this study was published

Published in 2013. Since then, CHS has become much more widely recognized, with larger case series and proposed diagnostic criteria published.

The bigger picture

CHS challenges the widespread perception that cannabis use carries minimal gastrointestinal risk. The condition appears to be dose and duration dependent, typically emerging after years of regular use, and it resolves only with sustained abstinence from cannabis.

Questions still open

  • What is the actual prevalence of CHS among long-term cannabis users? Are certain patterns of use (frequency, potency, route) more likely to trigger the syndrome? Why does hot water bathing provide temporary relief?

Common questions

What is cannabinoid hyperemesis syndrome?
CHS is a condition seen in long-term cannabis users, characterized by episodes of severe nausea and vomiting along with compulsive hot water bathing. It resolves with sustained cannabis abstinence.
Why do people with CHS take hot baths?
The exact mechanism was not well understood at the time of this review, but patients consistently report that hot water bathing temporarily relieves their nausea and vomiting symptoms.

Read the original research

Cannabinoid hyperemesis syndrome.

Hospital pharmacy, 48(8), 650-5

Citation

Sun, Shusen; Zimmermann, Anthony E. (2013). Cannabinoid hyperemesis syndrome.. Hospital pharmacy, 48(8), 650-5. https://doi.org/10.1310/hpj4808-650

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