The only reliable way to distinguish cannabinoid hyperemesis from cyclic vomiting syndrome is to stop cannabis and see if symptoms resolve | Research

The takeaway

A literature review found that complete and persistent symptom resolution after quitting cannabis is the only reliable criterion separating cannabinoid hyperemesis syndrome from cyclic vomiting syndrome, as even compulsive hot bathing occurs in both conditions.

Read this if you experience recurrent vomiting episodes and use cannabis, or want to understand the CHS-CVS diagnostic challenge.

Compulsive hot bathing occurs in both CHS and CVS, contradicting a common diagnostic assumption

What the researchers found

Cannabinoid hyperemesis syndrome (CHS) and cyclic vomiting syndrome (CVS) share nearly identical presentations: recurrent episodes of severe nausea, vomiting, and abdominal pain. The review found that compulsive bathing behavior, previously thought to be unique to CHS, actually occurs in CVS patients as well.

The only reliable distinguishing criterion is therapeutic: complete and persistent resolution of all symptoms following cannabis cessation confirms CHS. Supportive criteria for CVS include psychiatric comorbidities (panic attacks, depression), history of migraines, and rapid gastric emptying.

Long-term follow-up is essential but rarely conducted, making definitive differentiation difficult in practice. The authors developed a standard operating procedure for diagnosis and management applicable across healthcare settings.

Why it matters

Both CHS and CVS are poorly recognized by physicians, leading to delayed diagnosis and unnecessary testing. As cannabis use increases, CHS is becoming more common, but misdiagnosis as CVS (or vice versa) has treatment implications. The finding that hot bathing is not a reliable differentiator overturns a widely held clinical assumption.

The numbers in context

The only reliable criterion: complete symptom resolution after cannabis cessation = CHS. Supportive CVS criteria: psychiatric comorbidities, migraine history, rapid gastric emptying. Both syndromes feature compulsive bathing behavior.

How the study worked

Literature review using the LIVIVO search portal for life sciences. The review focused on identifying clinical features that distinguish CHS from CVS and developing a practical diagnostic and treatment approach.

What this study cannot tell us

Literature review with inconsistent source data. Many published CHS and CVS cases lack long-term follow-up. The diagnostic criterion of symptom resolution after cannabis cessation requires sustained abstinence, which is difficult for many patients. The standard operating procedure was not validated in a clinical trial.

How to read the evidence

Literature review providing diagnostic guidance. Useful synthesis but based on inconsistent case reports and limited long-term follow-up data.

When this study was published

Published in 2017. CHS diagnostic criteria continue to be refined as more cases are documented.

The bigger picture

CHS awareness has grown rapidly, but this review reveals that the diagnostic picture is more complicated than commonly taught. The overlap with CVS means that some patients diagnosed with CHS may actually have CVS triggered or worsened by cannabis, and some CVS patients who use cannabis may be incorrectly labeled as having CHS.

Questions still open

How many patients currently diagnosed with CHS actually have CVS? Are there biomarkers that could distinguish the two conditions without requiring prolonged cannabis abstinence? Does partial cannabis reduction (rather than complete cessation) resolve CHS symptoms?

Common questions

What is cannabinoid hyperemesis syndrome?

CHS is a condition where chronic cannabis users develop recurrent episodes of severe nausea, vomiting, and abdominal pain. It is paradoxical because cannabis is often used to treat nausea, yet in some chronic users it appears to cause it. Symptoms resolve completely when cannabis use stops.

Does hot bathing help with CHS?

Many CHS patients compulsively take hot baths or showers during episodes, which temporarily relieves symptoms. However, this review found that hot bathing also occurs in cyclic vomiting syndrome patients, so it cannot be used to diagnose CHS specifically.

Read the original research

Cannabinoid hyperemesis and the cyclic vomiting syndrome in adults: recognition, diagnosis, acute and long-term treatment.

German medical science : GMS e-journal, 15, Doc06

View on PubMed ↗Publisher’s paper ↗

Citation

Blumentrath, Christian G; Dohrmann, Boris; Ewald, Nils. (2017). Cannabinoid hyperemesis and the cyclic vomiting syndrome in adults: recognition, diagnosis, acute and long-term treatment.. German medical science : GMS e-journal, 15, Doc06. https://doi.org/10.3205/000247