Cannabinoid Hyperemesis Syndrome: When Heavy Cannabis Use Causes Severe Vomiting | Research

The takeaway

A case series documented four patients whose chronic cannabis use led to repeated episodes of severe nausea, vomiting, and compulsive hot water bathing, a pattern known as cannabinoid hyperemesis syndrome.

Read this if you use cannabis regularly and experience unexplained episodes of nausea or vomiting.

All 4 patients saw symptoms resolve after stopping cannabis

What the researchers found

The authors described four patients who experienced recurring cycles of intense nausea and vomiting that were linked to long-term, heavy cannabis use. All four patients engaged in compulsive hot water bathing, which temporarily relieved their symptoms.

Previous cases from the medical literature were reviewed alongside these four, confirming a consistent pattern: chronic cannabis use, cyclical vomiting episodes, and relief from hot showers or baths. Symptoms resolved when patients stopped using cannabis.

Why it matters

Cannabinoid hyperemesis syndrome is frequently misdiagnosed because cannabis is typically associated with reducing nausea, not causing it. This paradox means patients often undergo extensive and expensive diagnostic workups before the actual cause is identified.

The numbers in context

4 new cases described. All patients were chronic cannabis users. All exhibited compulsive hot water bathing. Symptoms resolved with cannabis cessation in each case.

How the study worked

This was a case series describing four patients seen at a single institution, combined with a literature review of previously published CHS reports. The authors analyzed the clinical presentations, proposed pathophysiological mechanisms, and discussed diagnostic challenges.

What this study cannot tell us

Case series provide descriptive evidence but cannot establish how common CHS is or identify which cannabis users are most at risk. The small number of cases limits generalizability. The pathophysiology remains hypothetical.

How to read the evidence

Case series with literature review; descriptive evidence only, no controlled comparison.

When this study was published

Published in 2012. CHS has since become widely recognized in emergency medicine literature.

The bigger picture

As cannabis use has become more widespread, reports of CHS have increased. The condition challenges the common assumption that cannabis is universally anti-nausea, revealing that chronic heavy use can produce the opposite effect in some individuals.

Questions still open

What makes certain chronic cannabis users develop CHS while others do not? Is there a dose or duration threshold? Could genetic factors explain individual susceptibility? Why does hot water bathing provide temporary relief?

Common questions

What is cannabinoid hyperemesis syndrome?

CHS is a condition where chronic, heavy cannabis users develop recurring episodes of severe nausea, vomiting, and abdominal pain. A hallmark feature is compulsive hot water bathing, which temporarily relieves symptoms. The condition resolves when cannabis use stops.

Why would cannabis cause vomiting if it is used to treat nausea?

The paradox likely involves how chronic exposure affects cannabinoid receptors in the gut differently than acute use. While short-term cannabis activates anti-nausea pathways, prolonged heavy use may dysregulate these receptors in the digestive system, producing the opposite effect.

Read the original research

Cannabinoid hyperemesis syndrome: a case series and review of previous reports.

Psychosomatics, 53(3), 212-9

View on PubMed ↗Publisher’s paper ↗

Citation

Nicolson, Stephen E; Denysenko, Lex; Mulcare, J Loretta; Vito, Jose P; Chabon, Brenda. (2012). Cannabinoid hyperemesis syndrome: a case series and review of previous reports.. Psychosomatics, 53(3), 212-9. https://doi.org/10.1016/j.psym.2012.01.003