Six New Cases of Cannabis Hyperemesis Took an Average of 6 Years to Diagnose | Research

The takeaway

Six new cases of cannabinoid hyperemesis syndrome at one Spanish hospital showed an average 6.1-year delay from symptom onset to diagnosis, highlighting persistent underrecognition of this condition.

Cannabis users experiencing unexplained cyclical vomiting and emergency clinicians.

6.1-year average delay from symptom onset to CHS diagnosis

What the researchers found

A Spanish hospital reported six cases of cannabinoid hyperemesis syndrome (CHS) diagnosed between 2012 and 2014, accompanied by a summary of the 83 cases published worldwide through June 2014.

The average time from onset of acute CHS episodes to correct diagnosis was 6.1 years at this hospital, compared to an average of 3.1 years in previously published cases. This extended diagnostic delay demonstrates that healthcare professionals continue to be unaware of this condition.

All cases showed the hallmark features: cyclical vomiting unresponsive to standard antiemetics, relief from hot water bathing, and resolution with cannabis abstinence.

Why it matters

The persistent diagnostic delay of over 6 years means patients undergo years of unnecessary testing, hospital visits, and suffering before the correct diagnosis is made. Greater clinical awareness could dramatically improve outcomes.

The numbers in context

6 new cases. Average diagnostic delay: 6.1 years (vs. 3.1 years in prior literature). 83 total cases published worldwide by June 2014, 4 previously from Spain.

How the study worked

Case series of six patients diagnosed with CHS at Mataro Hospital in Spain, with comparison to the 83 previously published cases worldwide through June 2014.

What this study cannot tell us

Small case series from a single hospital. The diagnostic delay may reflect local factors rather than universal patterns. The total number of published CHS cases (83 by 2014) likely represents a small fraction of actual cases.

How to read the evidence

This is a small case series providing preliminary evidence on diagnostic patterns, supplemented by a review of published cases.

When this study was published

Published in 2016. CHS awareness has improved since then, though diagnostic delays likely persist.

The bigger picture

Over a decade after CHS was first described in 2004, diagnostic delays remained substantial. The growing number of cases reported globally suggests the condition is more common than initially thought, but awareness among clinicians has been slow to develop.

Questions still open

Has increased awareness since 2016 reduced diagnostic delays? What percentage of chronic cannabis users eventually develop CHS?

Common questions

Why does it take so long to diagnose CHS?

Clinicians typically associate cannabis with anti-nausea effects, making it counterintuitive to consider cannabis as the cause of vomiting. Many patients also do not disclose cannabis use, and the cyclical nature of episodes can mimic other conditions.

How many people have been diagnosed with CHS worldwide?

By June 2014, only 83 cases had been published. However, this almost certainly represents severe underdiagnosis. As awareness has grown, reported cases have increased dramatically, and the true prevalence among heavy cannabis users is likely much higher.

Read the original research

Cannabinoid hyperemesis syndrome. A report of six new cases and a summary of previous reports.

Adicciones, 28(2), 90-8

View on PubMed ↗Publisher’s paper ↗

Citation

Contreras Narváez, Carla; Mola Gilbert, Montserrat; Batlle de Santiago, Enric; Bigas Farreres, Jordi; Giné Serven, Eloy; Cañete Crespillo, Josep. (2016). Cannabinoid hyperemesis syndrome. A report of six new cases and a summary of previous reports.. Adicciones, 28(2), 90-8. https://doi.org/10.20882/adicciones.776